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This article presents a morpho-structural map at 1:50,000 scale of the confluence area between three regional units: (1) the Burgalesa Platform (Mesozoic; Cantabrian Mountains), (2) the Duero Basin and (3) the Ebro Basin (Cenozoic foreland basins). The map covers an area of 527 km2 in north Iberia. Additionally, structural lineaments such as joints are well preserved and documented in the Upper Cretaceous sediments of the Burgalesa Platform, represented by four main sets regarding their orientation. The foreland basins are incised in Miocene materials by rivers that have developed a complex drainage system controlling the deposition of the most recent alluvial sediments, following the four structural orientations. The map, together with the analysis of orthophotos and a Digital Terrain Model, and outcrop-scale observations, have led us to document the influence of the Miocene to present-day compression and strike-slip tectonic regime on the configuration of the drainage system and the geomorphological features.

One of the concerns of underground CO2 onshore storage is the triggering of induced seismicity and fault reactivation by the pore pressure increasing. Hence, a comprehensive analysis of the tectonic parameters involved in the storage rock formation is mandatory for safety management operations. Unquestionably, active faults and seal faults depicting the storage bulk are relevant parameters to be considered. However, there is a lack of analysis of the active tectonic strain field affecting these faults during the CO2 storage monitoring. The advantage of reconstructing the tectonic field is the possibility to determine the strain trajectories and describing the fault patterns affecting the reservoir rock. In this work, we adapt a methodology of systematic geostructural analysis to underground CO2 storage, based on the calculation of the strain field from kinematics indicators on the fault planes (ey and ex for the maximum and minimum horizontal shortening, respectively). This methodology is based on a statistical analysis of individual strain tensor solutions obtained from fresh outcrops from the Triassic to the Miocene. Consequently, we have collected 447 fault data in 32 field stations located within a 20 km radius. The understanding of the fault sets' role for underground fluid circulation can also be established, helping further analysis of CO2 leakage and seepage. We have applied this methodology to Hontomín onshore CO2 storage facilities (central Spain). The geology of the area and the number of high-quality outcrops made this site a good candidate for studying the strain field from kinematics fault analysis. The results indicate a strike-slip tectonic regime with maximum horizontal shortening with a 160 and 50∘ E trend for the local regime, which activates NE–SW strike-slip faults. A regional extensional tectonic field was also recognized with a N–S trend, which activates N–S extensional faults, and NNE–SSW and NNW–SSE strike-slip faults, measured in the Cretaceous limestone on top of the Hontomín facilities. Monitoring these faults within the reservoir is suggested in addition to the possibility of obtaining a focal mechanism solutions for micro-earthquakes (M

This work presents a macroseismic analysis of the AD 1755 Lisbon Earthquake-Tsunami event by means of the combination of intensity data derived from the EMS-98 scale and the ESI-07 scale (Environmental damage). About 600 records of secondary earthquake environmental effects (EEEs) for the whole Spain have been used to define intensities, focused on the SW portion of the Iberian Peninsula. The Spanish data have been complemented with 308 EEEs records from Portugal. The analyses indicate maximum intensities of X EMS-ESI along the Atlantic margin of the Iberian Peninsula with 76 records of Tsunami environmental effects (TEEs). An important amplification (VIII – VII) occurred all along the Guadalquivir basin and the adjacent Betic front at epicentral distances of 300–700 km. In these zones 55 records of ground effects (ground cracks, Liquefactions and slope movements) are catalogued. In the rest of the territory of the Peninsula the most widespread effects were hydrogeological changes with 505 records in Spain and 196 in Portugal (total 701 records) covering all the intensity levels. Increase of flow discharges in springs and elevation of water level in wells was the common groundwater response to seismic shacking, especially in SW Iberia. In this zone water elevation in wells was between 5 and 3 m and persistent increases of discharges long-lasting (several days to two months). Persistent discharges on springs were linked in 143 cases to important SW-NE crustal faults (e.g., Alentejo-Plasencia Fault). From the Intensity distribution the historic seismic scenarios are explored by means of the development of empirical ShakeMaps. These consider the three classical seismic sources proposed for this earthquake: Gorringe Bank (G); Marques de Pombal Fault (M) and Atlantic delamination beneath the Gulf of Cadiz (C). However, individually these seismic sources are too small and unable to generate the resulting seismic scenario depicted by the intensity map developed in this work, with onshore seismic accelerations (PGA) up to 0.82 g. These acceleration values and the great amplification experienced throughout the Guadalquivir basin (0.34–0.52 g) are only possible considering a combination of the three seismic sources (GMC Source) probably related to shallow subduction or lithospheric delamination beneath SW Iberia and the Gulf of Cadiz. This will suggest an NNE-SSW offshore rupture length of 350–360 km with an overall rupture area of c. 84,500 km2 resulting in an event magnitude 8.6 Mw calculated from empirical relationships. The results demonstrate the efficacy of these kind of approaches for better identifying and modelling seismic sources for historical events, This work was supported by the Spanish Research Project MINECOFEDER CGL2015-67169-P (QTECSPAIN - USAL). It is a contribution of the Earthquake Geology Group (TPPT) of the INQUA TERPRO Commission. Authors are grateful to the constructive comments of Joao Fonseca and an anonymous reviewer who significantly improved the content of this paper

The "Caliphal City of Medina Azahara" was built in 936-937CE or 940-941CE (depending on the source) by the first Caliph of al-Andalus Abd al-Rahman III, being recently inscribed (2018) on the UNESCO World Heritage List. Its abandonment and destruction have been traditionally related to the civil war (“fitna”) initiated between the years 1009-1010. Besides that, other causes may have probably helped in the rapid depopulation and plundering of the city in the second decade of the 11th century, barely eight decades after its foundation. The archaeoseismological study carried out on the remains of the caliphal city provides the first insights on the possible intervention of an earthquake in the destruction and sudden abandonment of the city. The identified and classified Earthquake Archaeological Effects (EAEs) are dropped key stones in arches, tilted walls, conjugated fractures in brick-made walls, conjugated fractures and folds in regular pavements and dipping broken corners in columns. Up to 160 EAEs structural measures have been taken, the results of which are consistent with a mean ground movement direction of N140˚-160˚E. This geological structural analysis of preserved EAEs clearly indicates oriented damage, which can be reasonably related to the seismic destruction of Medina Azahara at the beginning of the 11th century, although other contributing causes cannot be ruled out., This files were generated by the Stereonet_Win_64 free sothware

This study presents a multidisciplinary approach to the tectonic geomorphology and history of the Palomares strike-slip fault in the Eastern Betic Cordillera (SE Spain). Analysis combines geomorphological mapping of fan-surfaces, pedological studies of faulted sedimentary successions, geoelectrical prospection and typical paleoseismological routines of structural analyses. Combined application of these methods together with the existing geochronological databases offer probable paleoclimatic and paleoseismic scenarios for the zone from Middle Pleistocene to Holocene. This study segments the Palomares Fault (PLF) in three overlapping “en echelon” N–S trends (PLF1, PLF2, PLF3). The older PLF1 controls the main faulted Almenara-Almagro range fronts. The younger PLF2 cuts and beheads crusted fan surfaces in the Aljibejo zone (ABJ). The intermediate PLF3 controls the development of intervening tectonic reliefs and offset paleosol sequences in alluvial-colluvial deposits. Our analysis focuses on the PLF3 at the La Escarihuela site (ESCH), where outcrops display eight faulted paleosols developed on overlapped Middle Pleistocene colluvial-alluvial deposits, with variable vertical slip of between 21 and 12 cm (bulk accumulated offset: 33 cm), evidence of two surface faulting events. After the structural analysis of the fault planes (striae plunges) net left-lateral displacements of 120.9 ± 3.3 cm (Event 1) to 69.1 ± 5.2 cm (Event 2), associated with maximum magnitudes of c. 6.7–6.5 Mw. However, the faulted sequence is sealed by a thick mature calcrete horizon of similar characteristics to that faulted at the ABJ1 site. Regional chronological data on calcic soils and calcretes in SE Spain assign this mature calcrete to Oxygen isotopic stages (OIS) 9 (c. 300 ka). With this age fixed at the uppermost of the faulted paleosol sequence at the ESCH site (PLF3), soil development features (clay and carbonate contents, thickness, reddishness, etc.) were used as paleoclimatic proxies to correlate soil horizons with conventional OIS. Correlation indicates that clayey Bt soil horizons primarily occurred during warm isotopic stages followed by recalcification and carbonate accumulation (Btk; Bk; Ck horizons) during latter warmer stages. A proposed theoretical geochronological framework suggests that the sedimentary sequence at the ESCH site (PLF3) was deposited between OIS 18 and 9. Major environmental change towards the present semi-arid climate occurred during OIS 13 (c. 500 ka). During this same stage, paleoseismic event 1 also occurred, but paleoseismic event 2 took probably place during OIS 10 (c. 350 ka), before development of the uppermost calcrete sealing the deformation in this fault segment. However, this OIS 9 calcrete is faulted in the ABJ1 and a younger less developed calcrete is faulted in ABJ2 on the PLF2 segment. Chronology proposed in this paper suggests theoretical ages for these events of between OIS 8-OIS 5 for ABJ1 (c. 200 ka) and between OIS 4 -OIS 2 for ABJ2 (c. 40 ka). This last paleoseismic event triggered major landscape changes with still-visible fault scarps, linear tectonic reliefs, alluvial fan beheading and active drainage shuttering. This present work illustrates the use of soil/paleosol analyses in paleoseismology as a useful tool to build paleoclimatic analogues and develop relative chronological frameworks from existing regional age data.

International audience; As recent dramatic and numerous examples demonstrate, earthquakes still constitute a significant threat to cultural heritage (Bam 2003, L’Aquila 2009, Haiti 2010, Nepal 2015). By damaging the historical legacy, telluric phenomena affect economic and touristic incomes and alter regional identities and collective psyche. In the Andes, as in other emerging regions across the globe, deficient seismic hazard assessments, constant lack of resources, and inadequate maintenance programs are additional challenges for cultural heritage management. As part of our archaeoseismological investigation in the Cusco area (Peru), we developed a relational database, which seeks to identify, record and inventory seismic damage in pre-Columbian architecture. This work presents the main characteristics of the structure and design of the RISC (“Risque sismique, Incas et Société à Cusco”) database and its contribution in supporting the fieldwork organization and facilitating the data acquisition. The collected architectonical evidence constitutes the first large archaeoseismological dataset in South America and will provide valuable complementary data in Peru to regional seismic hazard studies. We here aim to demonstrate that an ergonomic and user-friendly interface has a role to play in supervising and preserving the cultural heritage in active seismic areas. By converting ad-hoc surveys into routine inspections, RISC could become an effective low-tech monitoring system, providing relevant support for disaster risk reduction plans in archaeological sites conservation. We stress the necessity of adopting cost-effective and easy-to-implement tools for cultural heritage monitoring in emerging countries through this case study. Our database may represent a relevant methodological background and template for further initiatives in both fields of archaeoseismology and cultural heritage protection.

Slump, breccias, and turbidite deposits interbedded with diatomaceous marlstone and limestone occur in the upper part of the Late Miocene lacustrine succession of the Cenajo and Las Minas Basins. The basins display half-graben geometries where the northern margins consist of a network of large and deep, listric normal faults. The largest single deformational unit, reaching up 40 m in thickness, crops out in the Cenajo Basin and consists of soft-sediment deformed slump deposits displaying a variety of fold styles and geometries. This represents possibly the largest slump body hitherto described in fossil lake systems. The amplitude of the folds varies from meters in major folds to centimeters in the intrafolial minor ones. Brittle deformation of the slump strata is also common and cross cuts the ductile fabrics. Measured major fold axial traces indicate preferential N-S to NW-SE slide movement. The predominant strain in the deformed deposits is simple shear. Outcrops in the Cenajo Basin allow observation of extensional structures at the head slide, large sheath, and recumbent folds in the intermediate zone and tight compression structures at the toe, where folds and thrusts overrun the slightly deformed down slope strata. In contrast, the slump deposits in the Las Minas Basin are seen to pass down-dip into breccia and turbidite beds, which is indicative of flow transformation and internal disaggregation of the folded beds with distance. A number of laterally linked turbidite facies are recognized in the uppermost resedimented unit of the Las Minas Basin. The occurrence of these deposits points to marked instability in the lake basins. This period was preceded and followed by pelagic sedimentation of varve-like laminated, diatom-rich deposits. Most probably, basin instability was related to earthquake shocks, perhaps coeval to the extrusion of volcanic lamproite rocks in the region during the late Tortonian.

The long-term managing from the geological hazard point of view of the Hontomín onshore pilot-plant for CO2 storage, located in Spain and recognized as the first and only key-test facility in Europe, is one of the main objectives stated in the ENOS European project. This project is led and funded by the European Network of Excellence on the Geological Storage of CO2 (CO2GeoNet).The complex geological emplacement of the Hontomín Carbon capture and storage plant is considered rather relevant to analyse the impact of fracturing and both local and regional strain field on the reservoir parameters. The reservoir of Hontomín pilot-plant is formed by highly fractured Middle Jurassic dolomites with associated secondary porosity. This parameter is one of the main concerns when managing CO2 storage and monitoring.In order to characterize the fracture pattern and its implications on a proper CO2 monitoring, we characterized the surface structural elements through the study area and their relationship with fractures affecting the reservoir porosity. The methodology followed in this work is mainly based on detailed geological mapping (field work complimented with orthophoto analysis), adding missing information from previous works. This analysis does not increase the cost for long-term monitoring, given that they are low-cost and the results are acquired in a few months.The main structural trend in the study area, concerning faults with a wide range of displacement and metric to decametric folds, follows a regional E-W orientation. On the other hand, fractures show two main sets of trends, from NW-SE to NE-SW.This fracturing pattern, considered as a conjugate fracture system, corresponds to the tectonic stress recorded in both Mesozoic and Cenozoic sedimentary successions where the Hontomín pilot-plant is placed. Riddle faults formed from a nearby regional right-lateral strike slip fault (Ubierna Fault) are the responsible structures for the fracture system affecting the area and the reservoir. Moreover, this fracturing pattern is in agreement with local to regional active tectonic field from Cenozoic times to present-day, when the Ubierna Fault recorded its maximum right-lateral displacement (15 km).Secondary porosity within the reservoir can be produced from this fracture pattern, highly increasing the permeable migration paths for CO2 migration after the injection. Therefore, we state that a combination between fracture analysis and structural and tectonic study, should be considered as mandatory in the monitoring phases of the CO2 plume, during and after injection operations.

One of the concerns of underground CO2 onshore storage is the triggering of Induced Seismicity and fault reactivation. Hence, a comprehensive analysis of the tectonic parameters involved in the storage rock formation is mandatory for safety management operations. Unquestionably, active faults and seal faults depicting the storage bulk are relevant parameters to be considered. However, there is a lack of analysis of the active tectonic strain field affecting these faults during the CO2 storage monitoring. The advantage of reconstructing the tectonic field is the possibility to determine the strain trajectories and describing the fault patterns affecting the reservoir rock. In this work, we adapt a methodology of systematic geostructural analysis to the underground CO2 storage, based on the calculation of the strain field and defined by the strain field from kinematics indicators on the fault planes (ey and ex for the maximum and minimum horizontal shortening respectively). This methodology is based on statistical analysis of individual strain tensor solutions obtained from fresh outcrops. Consequently, we have collected 447 fault data in 32 field stations located within a 20 km radius. The understanding of the fault sets role for underground fluid circulation can also be established, helping for further analysis about CO2 leakage and seepage. We have applied this methodology to Hontomín onshore CO2 storage facilities (Central Spain). The geology of the area and the number of high-quality outcrops, made this site as a good candidate for studying the strain field from kinematics fault analysis. The results indicate a strike-slip tectonic regime with the maximum horizontal shortening with N160° E and N50º E trend for local regime, which activates NE–SW strike-slip faults and NE–SW compressional faults. A regional tectonic field was also recognized with N–S trend, which activates E–W compressional faults. Monitoring of E–W faults within the reservoir is suggested in addition with the possibility of obtaining focal mechanism solutions for micro earthquakes (M

The Historic Sanctuary of Machu Picchu (Cusco, Peru) is one of the most important archaeological monuments in Peru and worldwide. Machu Picchu is classified as a UNESCO World Heritage site and at risk from climatic change. However, the seismic centennial history of Peru reports large earthquakes generated both along the subduction zone (Mw8) and on active crustal faults along the Andean Cordillera (Mw7). It is therefore important to know if Machu Picchu is located in an area of seismic hazard and then to take measures to mitigate potential seismic hazards. Due to the short historical earthquake catalogue (< 500 years) and the absence of significant recent instrumental seismicity in the site's vicinity (radius of < 30 km), our knowledge about the seismic hazard in Machu Picchu is limited. The earthquakes of 1650 and 1950 affected Cusco city and surrounding areas, but without damage descriptions in Machu Picchu (80 km away) (Silgado Ferro 1978). In this study, we make the first attempt to use the analysis of earthquake archaeological effects (EAEs) and their differentiation from the effects generated by slope movements (creep) to investigate the past occurrence of strong earthquakes at the site. The application of geological structural analysis to the deformations observed in Machu Picchu shows two directions of the mean ground movement: N020 degrees E and N110 degrees E. Two earthquakes that affected Machu Picchu during its construction generated these directions. This kind of data should be used in the future to protect this important archaeological site.

The present paper analyzes different types of natural disasters recorded in the woody elements from reconstruction or repair works in two World Heritage buildings (the Old Mint and the Cathedral) in Segovia (Central Spain). We employed architectural and historical documentation, along with archaeoseismological analysis techniques in order to frame the events and processes. We analyzed several woody elements from the wooden deck of the Old Mint, including beams, planks and support blocks; and for the Cathedral roof the structural elements analyzed were tiebeams, raised aisles, rafter braces, common rafters and roof battens, as well as many planks and soulaces. For the dating, we combined two methodological approaches based upon dendrochronological techniques (dendroarchaeology and dendrogeomorphology) in an integrated study of the tree-rings series obtained. Furthermore, four wood samples (one from the Old Mint and three from the Cathedral) were dated by means of radiocarbon techniques. The results enable us to detect and corroborate the dates of at least two catastrophic flood events that affected the Old Mint (1695 and 1733). Additionally, we establish the unknown effects to date upon the Cathedral roof of the fire caused by the thunderbolt in 1614 and by the Lisbon earthquake in 1755. From the point of view of cultural heritage, these data are of great interest for the history of the reconstruction of the Old Mint and of the Cathedral of Segovia.

El análisis de los daños producidos por eventos sísmicos en yacimientos arqueológicos proporciona mucha información sobre terremotos antiguos e históricos que pueden mejorar los análisis de peligrosidad sísmica. En este trabajo se propone una metodología de análisis que permite cuantificar la deformación a partir de los daños observados en un yacimiento de forma que se pueda establecer su posible origen sísmico. Esta metodología consta de tres fases: (a) Identificación e inventario de daños, (b) cuantificación de la deformación y (c) incorporación de los resultados a los catálogos sísmicos. La primera fase consiste en inventariar y cartografiar los daños siguiendo la clasificación de efectos arqueológicos de terremotos (EAE). La segunda fase consiste en cuantificar la deformación de esos daños, estableciendo diferentes parámetros como la dirección de máxima deformación horizontal (ey). Este análisis se realiza a diferentes escalas: individualmente para cada EAE inventariado, para el conjunto de daños del mismo tipo de efecto, y finalmente para todo el yacimiento considerado. El grado de homogeneidad en los resultados nos permite establecer el origen sísmico de las deformaciones. Esta metodología se ha desarrollado en al yacimiento romano de Baelo Claudia (Cádiz, España) y se ha aplicado a diferentes terremotos históricos de la Península Ibérica. Para calibrar este análisis, la metodología se ha aplicado a dos terremotos instrumentales: el terremoto de Lorca de 2011 (5,1 Mw; Murcia, España) y al terremoto de Emilia Romagna de 2012 (5,9 Mw; Italia)., Departamento de Geología y Geoquímica, Facultad de Ciencias, Universidad Autónoma de Madrid, Instituto Geológico y Minero de España, Departamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca

Las culturas mesoamericanas prehispánicas del altiplano mexicano, y en concreto los imperios P’urhepecha y Azteca (Periodo Posclásico tardío, 1300 – 1500 AD), experimentaron grandes terremotos destructivos que dejaron una impronta en su sociedad y determinó tanto sus ritos espirituales como su urbanismo. Este trabajo describe varios paleoterremotos que los P’urhepechas experimentaron en la ribera del Lago de Pátzcuaro a partir de técnicas de paleosismología. Se constata que grandes bloques basálticos asociados a los ritos religiosos P’urhepechas fueron colocados en el bloque hundido de dos grandes rupturas superficiales de origen sismogénico que afectaron a la geografía del propio lago. Los P’urhepechas colocaron dos grandes bloques de roca basáltica de más de 1 m3 de volumen y con su superficie tallada para utilizarlos en sus ritos espirituales. Los estudios paleosísmicos sugieren que ocurrieron varios terremotos de magnitud entre M 6,5 y M 7 con ruptura superficial y probablemente con una migración de la orilla del lago (Garduño-Monroy et al., 2009 y 2011a). Además, este trabajo demuestra que dichos terremotos se suceden desde el periodo Preclásico (3000 BP). En tiempos posteriores, durante la conquista española, se esculpió en el bloque basáltico una gran cruz cristiana de tipo maltesa que correspondería con el proceso de evangelización cristiana a lo largo del siglo XVI en la zona de Michoacán, lo que afianza el significado espiritual de dichos bloques. En cualquier caso, estamos ante una de las manifestaciones humanas más antiguas de los efectos de los sismos sobre culturas ancestrales.

Este trabajo propone un modelo cinemático 3D de la confluencia de las placas tectónicas Norteamericana y Pacífica con las placas de Rivera y Cocos, centrado en la zona de convergencia de la Fosa Mesoamericana en el área de México. A partir del análisis de más de 1300 mecanismos focales de terremotos (M ≥ 5.5) obtenidos de la base de datos en abierto del programa Global Centroid-Moment-Tensor (CMT), se han aplicado diversas técnicas de geología estructural para obtener la distribución espacial de los tensores de deformación (ey, ex, ez) y del factor de forma (k’) de dichos tensores. Estas técnicas consisten en el estudio de los Diedros Rectos de los mecanismos focales y de la aplicación del Modelo de Deslizamiento, basados en la cinemática del deslizamiento sobre el plano de falla teórico asociado a cada sismo. Este análisis permite realizar un estudio tridimensional de la deformación mediante el agrupamiento espacial 3D de los diferentes tensores (análisis cluster), agrupando zonas homogéneas en estilos de deformación, junto con los diagramas triangulares de clasificación de mecanismos focales (Kaverina) en relación con la geometría de la subducción y de la presencia de flujos mantélicos. También se han calculado perfiles profundos de la deformación y del factor de forma (k’) en relación a la geometría de la subducción y las principales estructuras tectónicas. Los resultados muestran una zonación 3D influenciada por el ángulo de subducción y el aumento de la velocidad de convergencia hacia el SE, en relación al acoplamiento mecánico de la subducción, apareciendo menos terremotos inversos en la convergencia de la Placa de Rivera con la Placa Norteamericana, frente a la Placa de Cocos con la Placa Norteamericana. La geometría 3D propuesta es congruente con la distribución espacial de grandes terremotos, el ángulo de subducción, la presencia de corrientes mantélicas a 100 km de profundidad y la presencia de terremotos en fallamiento normal. Este modelo también podría explicar la presencia de terremotos anómalos como terremotos lentos y silenciosos en el Gap de Guerrero.

The Malaga basin contains an important geological record documenting the complex paleogeographic evolution of the Gibraltar Arc before, during and after the closure and desiccation of the Mediterranean Sea triggered by the “Messinian Salinity crisis” (MSC). Proxy paleo-elevation data, estimated from the stratigraphic and geomorphological records, allow the building of quantitative paleogeoid, paleotopographic and paleogeographic models for the three main paleogeographic stages: pre-MSC (Tortonian-early Messinian), syn-MSC (late Messinian) and post-MSC (early Pliocene). The methodological workflow combines classical contouring procedures used in geology and isobase map models from geomorphometric analyses and proxy data overprinted on present Digital Terrain Models. The resulting terrain quantitative models have been arranged, managed and computed in a GIS environment., Departamento de Geología, Universidad de Salamanca, España, Instituto Geológico y Minero de España, España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Departamento de Geología, Universidad de Alcalá de Henares, España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España

An archaeoseismological study of Tira del Lienzo (Totana, Spain) was undertaken. The site belongs to the Argar archaeological group (2200–1550 cal. B.C.; Bronze Age). It is located on the trace of the reverse left-lateral Alhama de Murcia fault (AMF) that was responsible for the 5.1 Mw 2011 Lorca earthquake. The constructive typology of the site consists of mortar-free irregular natural boulders (dry-set masonry) and differs from earlier archaeoseismological sites built on regular masonry constructions in the Betic Cordillera. Four Earthquake Archaeological Effects (EAEs) were identified as follows: (1) an apparent surface rupture (c. 18 cm left-lateral offset), (2) the differential coseismic uplift of several centimeters affecting the main building of the settlement, (3) the widespread development of fractures on the ground surface (ground cracks) in a NE-SW direction consistent with the kinematics of the AMF, and (4) fractures in boulders that constitute the remains of the dry stone walls at the site. Structural analysis of the two fracture types reveals two nearly orthogonal sets (NE-SW and NW-SE), matching the strike-slip kinematics of the AMF in the zone. Archaeoseismic evidence and related radiocarbon dates of the different building phases of the Bronze Age site indicate the probable occurrence of at least one strong seismic event (6.3–6.5 Mw; IX ESI-07) around 1550 cal. B.C., or soon after, triggering the destruction and probably the eventual abandonment of the site. We have identified an ancient lost earthquake from the Bronze Age and report the first archaeoseismological evidence of surface rupture in the Iberian Peninsula. This study also provides the first numerical data in the Totana-Alhama segment of the AMF based on the recorded archaeoseismic displacements. These data allowed us to characterize the related slip rates (0.05 mm/yr) to define the seismic potential of the analyzed fault segment of the AMF, which was poorly defined by previous seismic and geological data.

One of the most important geological effects generated by the seismic events of Emilia Romagna (Italy, 2012) was the liquefaction. The first earthquake took place on 20th May (5.9 Mw) and generated liquefaction in the locality of San Carlo, mainly recorded as large fissure sand volcanoes. Detailed stratigraphic and sedimentology analyses of these sand bodies indicated the assemblage of rhythmic normal graded beds of sand for many individual sand volcanoes. This is interpreted as repeated individual sand extrusions generating polygenetic sand blows for a single earthquake. This original analysis, made for first time in a case of extensive seismic liquefaction, indicates that the different pulses sand extrusion occurred after seismic shaking, and therefore no related to the cyclic seismic shearing stimulated by surface seismic waves. Underground liquefaction of shallow sandy layers and ground cracking, assisted by relevant lateral spreading, promoted water and sand ejections (E–W direction). Localised and repeated ground subsidence and bulging supported by the ejection of the underlying fluidized sediments feedback transient ground undulations and repeated sand ejections. The unstable undulating behaviour of the ground reinforced and sustained the liquefaction process through time after the seismic shaking, leading the occurrence of polygenetic sand volcanoes. In summary, the seismic liquefaction is the starting point of the process, although only if these sand ejections could promote the instability of the ground since underground sand depletions feedback the liquefaction process through time. The process stops when the hydrostatic balance is recovered in the affected zone.

Normally in paleoseismology, the study of the tectonic slip-rate is performed in trenches on the fault scarp, or by the estimation of fault movements from the geomorphic features. In this work, we have carried out a paleoseismic analysis of the Benis Fault, located in southeast Spain, combined with a geothermal analysis inside a deep cave related to the fault (−350 m). Thus, we have estimated the last earthquake magnitude and time of occurrence from evidence of ceiling collapse and displaced carbonate blocks inside a cave, which is developed across the fault. The magnitude was obtained from the application of the empirical relationship of the fault parameters and coseismic vertical displacement, yielding a value ranging between M 5.9 and M 6.5. Moreover, we dated this paleoearthquake by the paleontological record of a “Lynx pardinus spelaea”, with an age of 65 ± 18 ka BP. Additionally, we have measured the thermal profile of the Benis Cave (−350 m of depth), from single rock point temperature measurements during 2 years. The temperature profile shows three different parts inside the cave, the shallow heterogeneous thermal zone till 50 m depth; the homogeneous thermal zone 150 m till with constant temperature and the hetero-thermal deep zone, deeper than 150 m and till the deepest zone (350 m). Furthermore, we have estimated the Vertical Geothermal Gradient, 1.85 °C/100 m for the deepest zone (−150; −290 m). The temperature increases with depth, showing a reverse thermal profile in comparison with normal gradients in deep caves. Finally, we have calculated the heat flux of 0.46 mWm., This work is a contribution of the Spanish projects SISMOSIMA CGL2013-47412-C2-2-P and CGL2015-67169-P (QTETCSPAIN-USAL), granted by the MINECO-FEDER Spanish Ministry.

Earthquake Environmental Effects describe the geological features of an earthquake, including the surface faulting, ground cracks, soil liquefaction and landslides, among others. Historical large earthquakes could be classified according to the EEE macroseismic geological scale (ESI07), with the advantage that it is possible to compare different earthquakes which have occurred in different places and estimate the parameterization of their seismogenic sources. Hence, we have determined the ESI07 scale by the EEE description of the geological effects observed during the 1912 Acambay earthquake, which took place in the central basin of Mexico. Additionally, we have estimated the epicentral area of this earthquake, the total rupture length and the potential seismicity of the Acambay-Tixmadejé fault zone. Furthermore, we have estimated the earthquake archaeological effects (EAEs) of the oriented damage. To do this, we have modelled the S-wave travelling by assuming different epicentre locations at several active fault segments and thus, we have compared with the oriented damage mapped by Urbina and Camacho (1913) at different villages. Therefore, we propose a model of rupture of 1912 Acambay earthquake, releasing a M ≥ 7 earthquake and with the epicentre located at Tixmadejé. This rupture model implies earthquake directivity towards East and the S-wave travelling towards South. The total rupture length was estimated 33 km and the maximum coseismic offset 52 cm., Instituto Geológico y Minero de España, España, Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, México

This paper summarizes the content and scope of the “Catalogue of Earthquake Geological Effects in Spain”. The catalogue has been published by the Geological Survey of Spain (IGME) and constitutes the first official publication (in Spain) on seismic hazard containing geological information. The catalogue gathers the 51 stronger earthquakes that have occurred in Spain since the Neolithic period to the present and classifies earthquakes with geological or archaeological seismic records in paleoseismic, ancient, historical and instrumental earthquakes. The catalogue offers a variety of parametric information, quality indexes (Qe, Qi, Qg), and Environmental Seismic Intensity Scale (ESI-07) based description of environmental damage structured in individual “event files”. Sixteen of the 51 catalogued events present full information files (full event files), with individualized analyses of the geological and geoarchaeological data as well as graphic information with hybrid ESI-EMS intensity maps, ShakeMaps (seismic scenarios) and complementary kmz files (Google Earth) for each of the sixteen selected earthquakes; among which is the well-known AD 1755 Lisbon earthquake-tsunami. These selected earthquakes present individual environmental earthquake effects (EEE) or earthquake archaeoseismological effects (EAE) files for each catalogued effect containing specific site geo-information and graphic data (photos, graphs, maps, etc.). The second edition of the catalogue record 1027 EEEs and 187 EAEs, of which 322 effects have individual files.

The Arriaga Palaeolithic sites, located within the Middle–Late Pleistocene thickened terrace (TCMZ: + 18–22 m) of the Manzanares River valley (Madrid, Central Spain), were subject to intensive archaeological and palaeontological prospecting during the 1980s. Compilation of documents from these old excavations, together with new geoarchaeological, sedimentological, pedological and geophysical data, allow us to locate the morpho-stratigraphic position of the analysed sites within the overall stratigraphy of the TCMZ. This thickened terrace comprises two main fluvial sequences (Lower and Upper) topped by a thick (2.5–5 m) alluvial–colluvial formation. The fluvial sequences are stacked in the study site located in the lowermost reach of the valley, but display complex inset relationships upstream, where they are individualized in two different terrace levels at + 18–22 and + 12–15 m. Terrace thickening was primarily controlled by synsedimentary subsidence caused by dissolution of the evaporitic substratum and locally influenced and backfed by tectonic activity. The regional analysis of the dated (TL and OSL) fluvial sequences containing Palaeolithic sites within the TCMZ, together with new TL dates provided in this study, indicate that the three sedimentary sequences in the TCMZ are time-transgressive valley-fill bodies. Terrace thickening started before the Last Interglacial Period (MIS 6 or older) and continued during whole MIS 5 (lower fluvial sequence) and MIS 4 (upper fluvial sequence) reaching the MIS 3 (top alluvial formation), the latter characterized by the accumulation of alluvial–colluvial sequences derived from the main tributaries and valley slopes. The TCMZ records the Middle–Late Pleistocene boundary, but also the transition between the Lower and Middle Palaeolithic periods during the Late MIS 5 (ca. 96 to 74 ka). The studied Arriaga sites contain evolved Lower Palaeolithic industry (evolved Acheulean techno-complexes) and warm faunal assemblages located within the Lower fluvial sequence, but apparently well constrained Middle Palaeolithic sites are placed within the Upper fluvial sequence at other upstream locations. Deposition of the thickened alluvium was mainly controlled by the upstream advance of dissolution-induced subsidence phenomena, blurring the impact of Late Pleistocene climatic cycles and producing time-transgressive longitudinal valley-fill bodies (i.e. sedimentary sequences). Late Quaternary climatic changes only seem to control the incision/aggradation cycles after the termination of the TCMZ from the Late MIS 3. Dates related to the development of younger inset terraces indicate that they are apparently linked with cold Heinrich events H4 to H1. These younger inset terraces yield cold faunal assemblages and abundant Middle Palaeolithic “Mousterian” assemblages, Departamento de Geología, Escuela Politécnica Superior de Ávila, Universidad de Salamanca, España, Departamento de Arqueología, Paleontología y Recursos Culturales, Auditores de Energía y Medio Ambiente, S.A., España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Dirección General de Patrimonio Histórico, Comunidad de Madrid, España, Técnicas Geofísicas S.L., España, Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España, Área de Investigación en Peligrosidad y Riesgos Geológicos, Instituto Geológico y Minero de España, España

The recognition of seismically induced soft-sediment deformation structures (SSDS) in sedimentary successions characterized by different facies, and hence by different rheology, is challenging. This is the case for high porosity and high permeability aeolian facies interbedded with muddy wet interdune deposits and alluvial conglomerates and sandstones. Several types of SSDS have been studied in two exposures of the Upper Pliocene (2.9–2.6 Ma) sediments of a fault-bounded intracontinental aeolian dune field in the Teruel Basin (Iberian Chain, eastern Spain). Among SSDS, load and fluid-escape structures, apart from several animal tracks, have been recognized. Those structures show an irregular distribution through the studied stratigraphic sections, being scarce in homogenous aeolian sands and frequent in water-related facies. A detailed study of the distribution and geometry of SSDS and their relationships with respect to the stratigraphic architecture and facies has allowed a critical discrimination of trigger mechanisms, i.e. biological or physical overloading vs. earthquakes. The seismically induced structures are concentrated into seven deformed beds, showing an uneven lateral distribution and geometry closely controlled by the hosting sedimentary facies and their rheology. These seismites resulted from liquefaction during moderate earthquakes (estimated magnitude from 5.0 to 6.8). The most probable seismogenic source was the Sierra del Pobo normal fault zone, located 2 km to the East. Results show how an appropriate recognition of sedimentary facies is crucial to understand the lateral variability of seismites in sedimentary environments characterized by sharp facies changes., Grupo GeoTransfer, Universidad de Zaragoza, España, School of Applied Sciences, Faculty of Computing, Engineering and Science, University of South Wales, Reino Unido, Departamento de Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, España, Instituto Geológico y Minero de España, España

The ancient Roman city of Complutum(Alcalá deHenares,Madrid), founded in the 1st century AD,was one of the most important cities ofHispania. The old Roman citywas destroyed, abruptly abandoned, relocated close by and rebuilt during the late 4th century AD. Destruction of the city and its relocation has not yet been explained by archaeologists. In this paper,with ourmultidisciplinary approach, we identify and characterize earthquake archaeological effects (EAEs) affecting the archaeological site, the La Magdalena, an agricultural holding 4 km from the core of Complutum. The most important EAEs in the site are liquefactions (sand dikes and explosive sand-gravel craters) affecting Roman structures, such as water tanks (cisterns), houses and graves. Ground liquefaction generated significant ground cracks, explosive craters and folds in foundations of buildings. Several other Roman sites throughout the valleywere also abandoned abruptly during the 4th century AD, in some caseswith EAEs of similar origin. This suggests the occurrence of a 5.0–6.6 Mw seismic event in the zone, in accordance with the minimum empirical limit of seismically-induced liquefaction and the maximum surface rupture length of the Henares fault., Instituto Geológico y Minero de España, España, Departamento de Geología, Escuela Politécnica Superior de Ávila, Universidad Salamanca, España, Facultad de Ciencias, Universidad Autónoma de Madrid, España, Trébede, Patrimonio Cultural, S.L., España, Departamento de Ingeniería del Terreno, Escuela Politécnica Superior de Ávila, Universidad Salamanca, España, Departamento de Edafología, Universidad Politécnica de Madrid, España, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, España, Departamento de Geología, Universidad de Alcalá de Henares, España

During the 2000 and 2001 R/V Cornide de Saavedra cruises a vast field of hydrocarbon-derived carbonate chimneys was discovered and sampled along the Cadiz Contourite Channel and Guadalquivir Diapiric Ridge. Photographs taken on board using an underwater camera revealed a spectacularly high density of pipe-like chimneys lying on the sea floor, though some of them were also found protruding from muddy sediment. The major axes of the fallen chimneys, which can be as long as 1 m, exhibit a regular spatial distribution showing a conspicuous NW-SE trend. Furthermore, their basal morphology shows a characteristic angular breakage associated to a flexo-traction process. Both the uniform distribution of the major axis and the basal morphology of the chimneys imply that the cause of the rupture could be related either to strong bottom sea currents or to inertia forces associated with oscillatory ground motion due to seismic shaking. The preferential orientation of the broken chimneys, their mechanical properties, the geological and topographical conditions of the area in relation to seismic ground motion amplification and the flow speed of the Mediterranean Outflow Water (MOW) along the Cadiz Contourite Channel, suggest that the most probable cause of the chimneys’ rupture was an earthquake. The minimum magnitude of this seismic event is estimated to be more than 7.0, the causative fault being located directly under the chimney field or as far as 30–60 km away. The chimneys’ rupture took place between ca 5 ka to Present.

The Michoacan-Guanajuato Volcanic Field displays about 1040 monogenetic volcanoes mainly composed of basaltic cinder cones. This monogenetic volcanic field is the consequence of a dextral transtensive tectonic regime within the Transmexican Volcanic Belt (TMVB), the largest intra continental volcanic arc around the world, related to the subduction of the Rivera and Cocos plates underneath the North American Plate. We performed a statistical analysis for the size-distribution of the basal diameter (Wco) for cinder cones. Dataset used here was compiled by Hasenaka and Carmichael (1985). Monogenetic volcanoes obey a power-law very similar to the Gutenberg–Richter law for earthquakes, with respect to their size-distribution: log 10 ( N >= Wco ) = α − β log 10 ( Wco ), with β = 5.01 and α = 2.98. Therefore, the monogenetic volcanoes exhibit a (Wco) size-distribution empirical power-law, suggesting a self-organized criticality phenomenon.

Pronounced lacustrine sedimentation developed in west-central Mexico during the late Miocene, between approximately 11 and 7 Ma. This was in response to tectonic extension associated with the initial emplacement of the late Miocene substrata of the Trans-Mexican Volcanic Belt. Climatic conditions in west-central Mexico during this interval were relatively warm and humid based on the widespread distribution of interpreted lacustrine beds. Following a latest Miocene (8.0–5.4 Ma) stage of arid conditions and greatly reduced deposition of fine-grained lacustrine sediments, extensive, east–west oriented, relatively deep, perennial lakes ensued. They mark the early Pliocene (5.3–4.0 Ma). Lower Pliocene diatomites contain the same diatom species (e.g., Stephanodiscus carconensis and Tertiarius aff. baikalensis) found in rocks of this age in the western United States. The relatively warm and humid conditions that characterized this interval in central Mexico coincide with a period of high-latitude warming, higher global sea level, and a reduction in size of the Antarctic Ice sheets. Because the Central American Seaway persisted until at least the latest Miocene, it might have acted to increase precipitation in central Mexico. This could have continued into the earliest Pliocene. Mexican Pliocene mammalian faunas also support a savanna setting with moist and warm conditions prevailing at the time. Shallow lakes and fluvial conditions dominate after 4.0 Ma, until the end of Pleistocene. A combination of reduced precipitation, due to general global cooling and drying, as well as volcanic and tectonic processes, are presumed to have been the cause for this mid-Pliocene reduction in lake size and extent in central Mexico.

A new methodology is introduced to estimate the most probable epicentral area for a paleoearthquake interpreted from seismites within a Quaternary basin. Seismites were described from various detailed stratigraphic logs within the Tierras Blancas Basin (TBB), a Pleistocene lacustrine area located in the central part of the Trans-Mexican Volcanic Belt (TMVB). The lacustrine landscape evolution of TBB has been determined by the recent fault activity of the Morelia-Acambay Fault System (MAFS). The TBB is bounded by active normal faults striking E-W. This fault activity has generated soft-sediment deformation structures, sand, silt and gravel dikes, pillows, diapirs, and decametric slumps, disturbing the sedimentary infilling. From these seismites and their stratigraphic spatial correlation, five strong-moderate paleoearthquakes (E1–E5) have been established in the basin. The spatial distribution of these seismites exhibits a gradient of perturbation defined by the intensity of deformation. Three different degrees of intensity deformation (DDI) are associated with the liquefacted grain size sediments: I (silt liquefaction), II (silt and sand liquefaction), and III (silt, sand and gravel liquefaction). This spatial gradient indicates an increase of the energy involved from the seismic activity, related with the proximity of the source. Mapping the boundaries among these zones of deformation and interpolation of each DDI limit for paleoearthquake E4 was used to construct paleoseismic isolines of deformation as a potential indicator of the most probable paleoepicentral zone. A 1.5 km 2 elongate zone oriented NNW-SSE is the potential paleoepicentral area associated with paleoearthquake E4 within the TBB.

This work analyses the present-day principal strain orientation on the downgoing slab of the South America Plate (SAM) beneath the Sandwich Plate (SAND). The strain regime was deduced from the study of 331 earthquake focal mechanism solutions examined by fault population analysis methods. In the slab, the maximum horizontal shortening direction (ey) rotates in trend in a clockwise direction from NE in the north, to SE in the south. Based on this rotation, three different areas were defined according to the prevailing focal mechanism type: (1) the North Zone, with ey oriented N0588E and reverse and strike–slip focal mechanisms; (2) the Central Zone, with only reverse focal mechanisms and ey striking N0808E; and (3) the South Zone, with ey oriented N1068E and reverse and strike–slip focal mechanisms. The strain field in the North Zone of the SAND involves decoupling of the slab at approximately 70 km depth. In contrast, the South Zone edge slab exhibits no decoupling and it exhibits different geometry (hook-like shaped) from the North Zone. Finally, we define the dextral strike–slip component acting at the South Sandwich Fracture Zone (SSFZ), according to focal mechanism solutions and the regional tectonic configuration. The geometry and kinematics of a plate tectonic boundary can be defined using geophysical and tectonic data such as earthquake focal locations and focal mechanism characteristics. Earthquake distribution shows the approximate position of the tectonic boundary if it constitutes a single line (e.g. Bird 2003). The orientations of the principal strain axis can be deduced from the focal mechanism solutions of earthquakes occurring on the plate boundary (e.g. Capote et al. 1991; Giner-Robles et al. 2003a). This study analysed 331 earthquake focal mechanism solutions, located within the South Sandwich region (2005 Harvard Catalogue, HCMT). Fault population analysis methods have been applied to these focal mechanisms in order to establish principal strain orientations. Their spatial locations allow definition of the three-dimensional (3-D) variations of the strain field within the slab. The results from the strain field and stress tensors are discussed according to the regional tectonic setting, and with variations of the subduction style along the slab. These results are influenced by the tectonic context: two triple junctions near the south slab edge (FFT and FFR) and one in the north edge (FRT) (Fig. 1). Processes and features detected at the underthrusting lithosphere are different age of the slab edges at the north and south (Eagles et al. 2005), lithosphere warming and thermal anomalies (Cruciani et al. 2005). Anomalous mantle inflow in both areas has been also suggested (Livermore et al. 1997; Leat et al. 2004).

The Cordovilla basin, located within the frontal thrust belt of the Betic Cordillera, SE Spain, is an elongated NW–SE graben showing discrete surface rupture generated by Holocene paleoearthquake activity. A main and an antithetic normal, NW–SE trending, active faults bound the basin. Paleoseismological evidence is reported on upslope-facing scarps of the antithetic fault, acting as dams to runoff, which contributed to temporary lacustrine conditions, as well as sediment uplift. The fluvial network in the area shows a poor drainage activity, whereas a present lake is dammed by the antithetic fault. The modern landscape is controlled by Holocene faulting, modifying the geological environment according to earthquake occurrence, from flat alluvial plains to lacustrine local basins. The application of the diffusion dating technique to unconsolidated sediments for the antithetic fault scarp indicates an age between 1 and 2 ka. Various geometric parameters have been obtained in order to reconstruct the paleoseismic history of the Cordovilla graben basin. The surface rupture and fault-offset values are associated with discrete active morpholineaments, parallel to the Pozohondo Fault. The Tobarra–Cordovilla segment (the structural boundary of the Cordovilla Basin) was generated by earthquakes with magnitudes (Mw) greater than 6.0, based on Wells and Coppersmith fault scarp relations.

This work illustrates the state of the art on archaeoseismology of the ancient Roman city of Baelo Claudia (Tarifa, Cadiz) after nearly fifteen years of research. This ancient Roman site was affected by two earthquakes in the years AD 40–60 and AD 260–290 which promoted important urban and architectural changes and eventually the destruction and further abandonment of the city in AD 365–390. Earthquake Archaeoseismological Effects (EAEs) are catalogued, described and mapped in the entire monumental sector of the city mainly witnessing the last earthquake which occurred in AD 260–290. Mapping of oriented EAEs illustrate damage distribution all over the lower sector of the city, as well as the occurrence of suspect coseismic landslide and tsunami events. The structural analysis of oriented EAEs throughout the entire mapped sector suggests that the intervening ground motion was preferentially oriented in a SW to NE direction. The geoarchaeological analysis and some relevant archaeological anomalies, strongly suggest the occurrence of coeval tsunami events during both ancient earthquakes, pointing to the occurrence of an offshore seismic source SSW of the city. Several N-S normal faults have been identified around the Bolonia Bay area and some of them continue offshore SSW of Baelo Claudia. These faults with clear Quaternary activity can be considered as the more probable seismic sources for the events affecting the ancient Roman site and they are consistent with the mapped damage orientation displayed by the structural analysis of EAEs within the old Roman city.

Active tectonics within the Upper Tagus Basin is related to the lithospheric flexure affecting the Palaeozoic basement of the basin. This flexure displays NE-SW trending. Besides, this structure is in agreement with the regional active stress field defined by the maximum horizontal stress with NW-SE trending. In this tectonic framework, irregular clusters of instrumental seismicity (Mw< 5.0) fade in the zone bounded by the Tagus River and the Jarama River valleys. These clusters are related to major NW-SE trending faults of suspected strike-slip kinematics. Moreover, reverse faults with NE-SW trending are affected by the strike-slip system as well. Despite the reverse faults are in agreement with the present SHMAX orientation, though, they apparently are blocked as seismogenic sources (scarce instrumental seismicity recorded today). In addition, we have determined the regional and local stress/ strain fields and two different fracture patterns were observed. Hence, we have divided the area in two zones: (1) the lateral bands of the basin, defined by reverse faulting (NE-SW trending) and strike-slip faulting (NW-SE trending) and (2) the central zone of the basin characterized by shallow normal faulting and NE-SW trending strike-slip faults. Furthermore, surface faulting and liquefaction structures are described affecting Middle to Late Pleistocene fluvial deposits, suggesting intrabasinal palaeoseismic activity (5.5 < M < 6.5) during the Late Quaternary. The obtained structural and tectonic information has been used to classify and characterize the Upper Tagus Basin as a semi-stable intraplate seismogenic zone, featured by Pleistocene slip-rates < 0.02 mm/yr. This value is low but it affords the occurrence of Pleistocene paleoearthquakes.

Universidad Complutense de Madrid, España, Universitat de Barcelona, España, Instituto Geológico y Minero de España, España

Instrumental and historical seismicity in the Albacete province (External Prebetic Zone) has been scarcely recorded. However, major strike-slip faults showing NW-SE trending provide geomorphologic and paleoseismic evidence of recent tectonic activity (Late Pleistocene to Present). Moreover, these faults are consistently well oriented under the present stress tensor and therefore, they can trigger earthquakes of magnitude greater than M6, according to the lengths of surface ruptures and active segments recognized in fieldwork. Present landscape nearby the village of Hellin (SE of Albacete) is determined by the recent activity of the Pozohondo Fault (FPH), a NW-SE right-lateral fault with 90 km in length. In this study, we have calculated the Late Quaternary tectonic sliprate of the FPH from geomorphological, sedimentological, archaeoseimological, and paleoseismological approaches. All of these data suggest that the FPH runs with a minimum slip-rate of 0.1 mm/yr during the last 100 kyrs (Upper Pleistocene-Holocene). In addition, we have recognized the last two major paleoearthquakes associated to this fault. Magnitudes of these paleoearthquakes were gretarer than M6 and their recurrence intervals ranged from 6600 to 8600 yrs for the seismic cycle of FPH. The last earthquake was dated between the 1st and 6th centuries, though two earthquakes could be interpreted in this wide time interval, one at the FPH and other from a far field source. Results obtained here, suggest an increasing of the tectonic activity of the Pozohondo Fault during the last 10,000 yrs., Instituto Geológico y Minero de España, España, Universidad Michoacana de San Nicolás de Hidalgo, México, Facultad de Ciencias, Universidad Autónoma de Madrid, España, Departamento de Geología, Escuela Politécnica Superior de Ávila, Universidad de Salamanca, España, United States Geological Survey, Estados Unidos

One of the key tasks in archaeoseismolo`gy is to test whether the recorded building damage in ancient cities can be related to ancient earthquakes. Archaeologists often claim abandonment, ruin or war instead of natural causes to explain the recorded damage in archaeological findings. This work proposes a comprehensive classification of Earthquake Archaeological Effects (EAE) based on the seismic deformation of buildings and monuments within urban areas of ancient cities. Accordingly, the proposed EAE classification differentiates the seismic deformation on the structure of buildings in two groups: from transient shaking and from permanent ground deformation. The first type of EAE corresponds to fractured walls and fallen key stones in arches, for example. The second type of EAE are tilted walls and shock breakouts of flagstones due to basement failure. To illustrate the proposed EAE classification, examples of earthquake damage on ancient buildings are described: Baelo Claudia and Tolmo de Minateda cities (Roman and Visigothic Periods, 1st–6th century AD, respectively, South of Spain) and Teotihuacan and Tarascan sites (Early Classic ca. IVth century AD, and Upper Post-Classic Period XIIIth century AD, Central Mexico).

The ruins of the ancient settlement of “El Tolmo de Minateda” are one of the best representative archaeological sites within the Albacete Province (SE Spain), characterized by a well-preserved record for the last ~3800 yr. The present ruins record an almost continuous of occupation from the Late Bronze Age (Iberian Culture, from ca. third century B.C.) to the High Middle Ages, including intervening and successive Roman, Visigoth, and Muslim city remains. The eventual Muslim settlement was

"El estudio de los efectos de sitio en el centro sur de México ha tomado una importancia vital debido a los grandes acontecimientos sísmicos de su historia. El sismo de 1985 reveló aspectos fundamentales de un efecto de sitio en una zona lacustre. A lo largo del Cinturón Volcánico Mexicano (CVM) y sobre todo en zonas de formación de cuencas lacustres, los efectos de sitio han generado daños en obras civiles y gran impacto en la población. En este trabajo se aborda el tema de los efectos de sitio en la población de Pátzcuaro, la cual se encuentra localizada dentro de una serie de cuencas lacustres formadas a lo largo de estructuras NE-SO y E-O del sistema de fallas Morelia-Acambay en el centro-sur de México. En Pátzcuaro, como seguramente en otros sectores del CVM, se encuentran zonas urbanas que se han desarrollado sobre derrames de lava provenientes de conos monogenéticos; estos derrames están conformados por alternancias de lavas en bloque y brechas volcánicas, las cuales cubren secuencias lacustres depositadas en lagos que se desarrollan bajo estos escenarios de vulcanismo y tectonismo. Se presentan primeramente los resultados de un estudio geológico y de paleosismología llevado a cabo en el sur del lago de Pátzcuaro, poniendo énfasis en las estructuras con evidencias de actividad sísmica histórica y prehistórica. Los resultados sugieren que la zona estuvo sujeta a diferentes eventos sísmicos, uno de ellos (M=7.3), durante el Pleistoceno, pudo haber generado el colapso del sector norte del volcán El Estribo y un depósito de avalancha de rocas. En 1858, el centro de México y sobre todo las poblaciones de Morelia y Pátzcuaro resintieron otro evento sísmico mayor. Con el propósito de caracterizar adecuadamente la respuesta sísmica de asentamientos urbanos importantes en estos ambientes geológicos, se realizaron estudios de zonificación sísmica y evaluación de la respuesta de sitio mediante estudios de vibración ambiental, provocada por fuentes naturales y actividad humana, que da lugar a microtremores, y a partir de éstos se hizo una zonificación. Con los cocientes espectrales de las componentes horizontal y vertical (H/V) de los microtremores y aplicando el método de Nakamura (1989) se estimaron periodos dominantes. Los resultados obtenidos demuestran que, no obstante el sustrato rocoso de la población de Pátzcuaro, existe una respuesta de sitio particular en la parte central y en la porción este del centro de la ciudad, donde los suelos presentan periodos dominantes de 0.2 a 0.6 segundos. Estos periodos podrían representar un riesgo potencial de resonancia para las construcciones existentes en esta zona. Finalmente se presenta un mapa de peligro sísmico, el cual toma en cuenta las características geológicas, los antecedentes históricos y prehistóricos de eventos sísmicos y los resultados de la zonificación sísmica."

This work describes the coseismic ceiling block collapse within Benis Cave (−213 m; Murcia, SE Spain), associated with the 1999 Mula earthquake (mb=4.8, MSK VII). The collapse occurred at −156 m into the Earthquake Hall, and as a consequence one small gallery became blind. We studied the geology, topography and active tectonic structures relevant to the cave. In addition, we carried out a seismotectonic analysis of the focal mechanism solutions, and also a fault population analysis on slickensides measured in fault planes in the cave. The stress and strain regime is interpreted as being congruent with the palaeoseismic evidence, and agrees with the fault kinematics established for cave galleries developed within fault planes and growth anomalies of coral flowstone. Our analysis suggests that one active segment (NNE–SSW) determined the morphology and topography of the Benis Cave, where strong to moderate palaeoearthquakes (6≤M≤7) took place. As a consequence of this intense seismic activity a small gallery collapsed. A new palaeoseismic structure, or seismothem, has been recognized, namely the effect of palaeoearthquakes affecting the pattern of development of the spatial coral flowstone distribution located at the bottom of the cave.

El sistema de fallas Morelia-Acambay (MAFS) consiste en una serie de fallas normales de dirección E-W y NE-SW que cortan la parte central del Cinturón Volcánico Transmexicano. El sistema de fallas se asocia a la formación de las depresiones lacustres de Chapala, Zacapu, Cuitzeo, Maravatio y Acambay. Las fallas E-W de MAFS aparecieron hace 7-9 millones de años durante Mioceno temprano. Las fallas NNW-SSE son más viejas y se han reactivado en el tiempo, desplazando y controlando a las depresiones lacustres E-W. Se estimaron las magnitudes sísmicas de las estructuras E-W de la región de Morelia-Cuitzeo asumiendo una ruptura cosismica. Cartografía, geología estructural y paleosismología sugieren que las estructuras de MAFS en la región de Morelia-Cuitzeo han estado activas durante el Holoceno, controlando los terremotos históricos que afectan a paleosuelos con cerámica de las culturas Pirinda-Purepecha. Estos terremotos históricos también están registrados en las fallas E-W del campo geotérmico de Los Azufres. En la región de Pátzcuaro, las estructuras E-W de MAFS también se ligan a sismos fuertes ocurridos durante épocas prehistóricas e históricas. Por ejemplo, la secuencia lacustre de Jarácuaro, en el sector meridional del lago Pátzcuaro ha registrado por lo menos tres sismos importantes (Período de PostClassic, 1845 y 1858). El sismo de 1858 (Magnitud estimada de ~7.3) generó un tsunami de 2 m de altura descrito en los archivos históricos. Un sismo similar en la actualidad devastaría esta zona del estado de Michoac’an, la cual está ocupada por las poblaciones de más alta densidad. De hecho, el 17 de octubre de 2007 mientras que este articulo era escrito, ocurrieron tres sismos en la ciudad de Morelia que fueron ligados a la falla normal derecha de la Central o de La Paloma. Este hecho corroboraba la sismicidad potencial de las fallas E-W y NE-SW del TMBV.

El actual lago de Pátzcuaro tiene una elevación de 2035 m sobre el niel del mar. Históricamente, ha alcanzado ha alcanzado una elevación de 2041 m, lo cual aislaba una porción de la isla cerca de la población de Jarácuaro en la parte sureste del lago. Dos trincheras realizadas en la antigua isla revelan secuencias estratigráficas tripartitas similares. En una trinchera de 3.1 m de profundidad, la secuencia de la base a la cima está formada por la Unidad A que comprende arcillas y limos ricos en diatomeas plegados y fallados con capas de arena volcánica. Estos depósitos están fechados entre 24 y 10 mil años BP. Unidad B que comprende una mezcla caótica de arenas volcánicas y lapilli, con abundantes restos de peces, bivalvos, gasterópodos y ostrácodos, de 10 cm de espesor con un contacto erosivo sobre la Unidad A. Los ostrácodos incluyen valvas articuladas con una mezcla de especies pelágicas de agua profunda y especies litorales. Los fragmentos de artefactos cerámicos pertenecientes al Periódo Post-Clásico (900 a 1520 AD) son abundantes. La Unidad C comprende una unidad de 20 cm de espesor de limo arcilloso rico en materia orgánica con restos de gasterópodos, semillas, líticos angulares y fragmentos de piezas cerámicas del Post-Clásico. La Unidad B sugiere una resedimentación catastrófica de los depósitos del piso del lago atribuidos a un tsunami. La Unidad C es consistente con condiciones sublacustres que están históricamente documentadas de 1858 a 1947. Un tsunami en el Lago de Pátzcuaro en 1858 ha sido registrado históricamente. El tsunami pudo haber sido creado por movimientos de falla o colapso del flanco suroeste de la isla de Janitzio. La ola del tsunami pudo haber contribuido al rápido aumento del lago de Pátzcuaro después del evento sísmico de 1858.