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The distribution of rare alkalis (Li, Rb, and Cs) is analyzed in spatially linked water objects of the Baikal geosystem: water of Baikal and its tributaries, underground water from boreholes and thermal springs, and the Angara River (the sole outlet), which are located in the Baikal rift zone. The rare alkali content differs significantly in some water objects, but the average and median contents are similar in the surface and deep water of Lake Baikal and the Angara River. The water of Barguzin thermal springs of the eastern shore of Lake Baikal contains the maximum amount of rare alkalis, but this affects the Baikal water insignificantly due to its natural self-cleaning and deep renewal of water during geodynamic movements. The similar rare alkali contents of Barguzin and some thermal springs of Kamchatka emphasize their indicator role in the genesis of water objects. [ABSTRACT FROM AUTHOR]

The science of volcanology advances disproportionately during exceptionally large or well-observed eruptions. The 2018 eruption of Kīlauea Volcano (Hawai'i) was its most impactful in centuries, involving an outpouring of more than one cubic kilometer of basalt, a magnitude 7 flank earthquake, and the volcano's largest summit collapse since at least the nineteenth century. Eruptive activity was documented in detail, yielding new insights into large caldera-rift eruptions; the geometry of a shallow magma storage-transport system and its interaction with rift zone tectonics; mechanisms of basaltic tephra-producing explosions; caldera collapse mechanics; and the dynamics of fissure eruptions and high-volume lava flows. Insights are broadly applicable to a range of volcanic systems and should reduce risk from future eruptions. Multidisciplinary collaboration will be required to fully leverage the diversity of monitoring data to address many of the most important outstanding questions. Unprecedented observations of a caldera collapse and coupled rift zone eruption yield new opportunities for advancing volcano science. Magma flow to a low-elevation rift zone vent triggered quasi-periodic step-like collapse of a summit caldera, which pressurized the magma system and sustained the eruption. Kīlauea's magmatic-tectonic system is tightly interconnected over tens of kilometers, with complex feedback mechanisms and interrelated hazards over widely varying timescales. The eruption revealed magma stored in diverse locations, volumes, and compositions, not only beneath the summit but also within the volcano's most active rift zone. [ABSTRACT FROM AUTHOR]

Recent geodetic data has clearly imaged significant contraction of rift zones during effusive eruptions, which is attributed to deformation of active, elongated feeders, challenging the rigid conduit paradigm. In this work we develop a physical model to understand the impact of conduit deformation on the eruptive dynamics. Numerical calculations show that magma overpressure increases the width of the conduit, resulting in higher discharge rates than would be expected from the rigid case. At the same time, conduits with high aspect ratio, have larger compressibility and can store significant amount of magma, thereby acting as secondary reservoirs. The net result is that rift zones can maintain high fluxes over prolonged periods of time, leading to large volume eruptions and biasing magma compressibility estimates. We apply our findings to the 2018 Kīlauea eruption where episodic collapse of the summit led to pressure pulses that propagated down‐rift and that were recorded by both tiltmeters and peaks in the effusion rates. Inversion of the data indicates a conduit with a height of 700–800 m and a maximum opening of 4 m, located at a depth of 2.5 km in the Upper East Rift Zone, becoming shallower in the Puʻu ʻŌʻō region and propagating sub‐horizontally in the Middle and Lower East Rift Zone. Based on these properties we infer that up to 30% of the erupted volume can be attributed to magma stored in the rift zone. In agreement with recent studies, we find that magma over‐pressure was low at the end of the 2018 eruption. Plain Language Summary: Deformation of the volcanic edifice shows a contraction of the conduits feeding eruptions. We have developed a physical model to understand how such deformation affects the amount of magma extruded and for how long the eruption will last. The results of the model indicate that elastic conduit deformation allows for larger volumes of magma to surface more quickly, compared to cases where the conduit behaves rigidly. One important finding was that elastic conduits act as secondary magma reservoirs. We applied the model to estimate the properties of the storage and transport system of the 2018 Kīlauea eruption. We found that the conduit had a height of about 750 m and a maximum opening of 4 m. The conduit is located at a depth of about 2.5 km in the Upper East Rift Zone, becoming shallower in the Pu'u 'Ō'ō region and propagating sub‐horizontally in the Middle and Lower East Rift Zone. As much as 30% of the total erupted volume could have originated from the conduit itself. Indeed, the pressure that drove the flow of the magma was low at the end of the eruption. Key Points: Geodetic data show significant deformation of rift zones during eruptionsA physical model of elastic conduit is derived to understand deformation effects on eruption dynamicsThe model is applied to 2018 Kīlauea eruption to invert the parameters of its plumbing system [ABSTRACT FROM AUTHOR]

Late Mesozoic and Cenozoic geodynamics of the Arctic region is discussed in the context of possible mechanisms which provide multistage cyclic transformations and transport of carbon through crust and mantle. Geodynamic processes control the abiogenic generation of hydrocarbons and the patterns of their localization. Possible mechanisms of abiotic hydrocarbon generation are explained in the context of carbon transport from subduction zones to rifts and serpentinization of ultramafic rocks in the rifts in the case of the Laptev Sea and Gakkel Ridge areas. The carbon of shallow crust origin migrates with encapsulated fragments of marine sediments which are consumed in the Pacific subduction zone where they become destroyed and transformed by different chemical and physical processes. The resulting C-species are involved in mantle convection flows and reach the continental rifts of the Laptev Sea and the Gakkel mid-ocean ridge. Thus, the hydrocarbons formed in the crust and in the mantle acquire signatures of abiotic origin. According to the authors, the scale of manifestation of abiogenic methanogenesis in the lower parts of the lithosphere and in the upper mantle is not so wide. Numerous small (mm and fractions of the mm) particles of exogenous matter and dispersed carbon pulled into the mantle can only form a stable crustal geochemical plume that propagates in the plane of movement of convective flows. Indirectly, the scale of manifestation of this process can be judged by the volumes of degassing of hydrocarbon and carbon dioxide gases, as well as hydrogen and its compounds in the rift systems of the earth's crust, which are extremely insignificant. However, in the cold seas of the Eastern Arctic, massive emissions of bubble methane of mixed genesis were found. As shown in the literature, the range of variability of stable isotopes of carbon and 14C of methane in certain areas of discharge associated with rifting demonstrates values (anomalously heavy 13C, and young 14C) that can be considered as examples of presumably abiogenic origin. Our work is mostly theoretical and suggests further discussion and improvement of the mechanism of formation of abiogenic hydrocarbons and the processes of their transformation. [ABSTRACT FROM AUTHOR]

Bathymetry and acoustic imagery swath mapping, along with observations and samples from four manned submersible and four ROV dives, confirm that a seafloor slope break on the northern approaches to Kaiwi Channel, between the islands of Oʻahu and Molokaʻi, Hawaiʻi is a former shoreline, now submerged ∼800 m below present sea level. Subaerially emplaced, low-relief basaltic lavas above the slope break transition to submarine morphologies below. The entire region has been tilted about 1° to the SSE (150°), and is cut by an 8–15 m-high, north-facing scarp, 100–400 m south of the slope break. The distribution of platy, table-top, and rarer mounded branching corals indicates the former presence of fringing reefs around low-relief paleo-islands. We infer that the regional tilt resulted from loading by younger Hawaiian volcanoes, compounded by flexural uplift and back tilting away from the unloaded footwall of a flank landslide to the north. Basalt samples collected from both above and below the slope break have petrography, chemical composition, and age (1.64–1.80 Ma) indicating correlation with the (late-shield) Lower Member of the East Molokaʻi Volcanics, rather than with the more proximal volcano of West Molokaʻi. The most likely source of the Kaiwi basalts is a submarine ridge (rift zone) that extends northwest away from ʻĪlio Point on West Molokaʻi. Although the submarine ridge was previously assumed to be an extension of West Molokaʻi's northwest rift, we conclude that regional bathymetry and gravity are consistent with this feature being an extension of the west rift of East Molokaʻi. A corallary of this interpretation is that the shoreline slope break (SSB 7 of Taylor, 2019) in this area is distinct from and younger than the southern SSB 7 formed on West Molokaʻi volcano (∼1.65 Ma vs. ∼1.8 Ma). • A seafloor slope break beneath Kaiwi Channel at ∼800 m below sea level was a shoreline ∼1.65 Ma. • Basalt samples from there are correlative in composition and age with late-shield lavas from East Molokaʻi. • Their most likely source is an extension of the west rift zone of East Molokaʻi along a submarine ridge NW of ʻĪlio Point. [ABSTRACT FROM AUTHOR]

Parga Chasmata is a 10,000 km long rift system on Venus with abundant coronae (enigmatic circular tectonomagmatic features). In order to further investigate the rift-corona relationship, detailed 1:500,000 geological mapping was focused on Onenhste Corona and the surrounding region (16°-24° S, 145°-131° W). More than 46,000 extensional lineaments were mapped and grouped into 50 sets, comprising 17 radiating, 28 circumferential and 5 linear sets (interpreted to overlie mafic dyke swarms). Radiating and circumferential swarms are linked with Onenhste Corona (OC), Momu Coronae (MC), Ulgen-ekhe Coronae (UEC), Rzhanitsa Corona (RzC, centred just outside the study area) and 5 Unnamed Coronae (UC1–5), as well as Malibran Patera (MP) and Fedchenko Patera (FP). Linear swarms are provisionally linked with magmatic centres outside the study area. Crosscutting relationships between the graben sets (dyke swarms) were used to identify the relative ages of magmatic centres. We applied an additional approach to recognize coeval centres, the swinging or deflection of radiating and circumferential dyke swarms to reveal the stress interaction between different coeval centres. The relative ages (oldest to youngest) of the magmatic centres are UC2 > RzC > MC ≥ OC = UC1 = UEC ≥ MP > UC5, and FP > UC3. These new detailed data provide significant information on coronae timing, evolution and relation to rift zones that will serve as a basis for future quantitative studies of lithospheric and mantle evolution and the combined cause and effect of rifting and mantle diapiric upwelling. Several centres, RzC, UC2, MC, UC3 and FP, ordered from NW to SE, are aligned along a trend parallel to Parga Chasmata but offset about 900 km to the south from the main zone of rifting. It is inferred that this alignment is related to a zone of weakness associated with the rift extension. Along this trend the centres do not show an age progression. Coronae MC, OC, UC1 and UEC are aligned along the NNE trending P13 Linea, orthogonal to the main Parga Chasmata rift. The main centre, Onenhste, is coeval with UC1, which in turn is coeval with UEC. Additional age relationships indicate that the late stage of OC was active at the same time as MP, MC and the UC2–9 centre of UC2. Linea P13 is older than Chondi Chasma. This study, and continuing, detailed geological mapping and analysis are increasing our understanding of the relationships between the formation of the main WNW trending Parga Chasmata rift zone, the orthogonal trends of rifting and the numerous magmatic centres (mainly coronae) distributed along both trends. • Dyke swarm history of coronae-rich study area south of Parga Chasmata. • 46,000 lineaments grouped as 17 radiating, 28 circumferential, 5 linear dyke swarms. • Swings in radiating & circumferential swarms– stress interactions between centres. • RzC, UC2, MC, UC3 & FP coronae aligned parallel to Parga Chasmata but offset 900 km. • MC, OC, UC1 and UEC corona aligned orthogonal to the Parga Chasmata trend. [ABSTRACT FROM AUTHOR]

ABSTRACT: The Beishan rift zone in Xinjiang Uygur Autonomous Region was formed due to strong activities of faults on the basement of the Tarim continental crust. Despite the fact that many geological research results of the rift zone have been achieved, only a few studies have been conducted on its regional geophysical characteristics. In this paper, the gravity and magnetic anomalies of the rift zone were highlighted through specific data processing of 1:50000 high-precision aeromagnetic data and gravity data with a grid spacing of 2 km × 2 km. Based on this, the geophysical evidence for the scope and internal structures of the Beishan rift zone was obtained for the first time. The distinct characteristics of magnetic and gravity fields in the areas to the north and south of the Beishan rift zone reveal that deep faults exist between the Beishan rift zone and the geological units on the southern and northern sides. Furthermore, the faults on the two areas contain the bidirectional thrusts and have flower-shaped structures according to the characteristics of the magnetic and gravity fields. The Beishan rift zone can be divided into two tectonomagmatic zones, namely the Zhongposhan-Bijiashan-Cihai-Baishanliang zone (the northern zone) and the Bayiquan-Qixin-Baishan zone (the southern zone). The northern zone can be further subdivided into three comet-shaped anomaly groups (tectonomagmatic areas), while the southern zone can be further subdivided into two tectonomagmatic areas. According to the characteristics of aeromagnetic anomalies and gravity field, 19 mafic-ultramafic complexes were delineated. The known Pobei, Hongshishan, and Qixin complexes are all located within the inferred complexes, with estimates of total explored resources of Ni, Cu, and Au of 3×106 t, 10×103 t and 10 t, respectively. The prospecting of high-grade copper-nickel deposits should focus on the periphery and deep parts of the known and inferred mafic-ultramafic complexes. Among them, the peripheral strata of the complexes specifically have great prospecting potential of large-scale high-grade copper-nickel deposits of magma injection type. Finally, this paper analyzed the application effects of the rapid airborne-ground-drilling synergetic exploration method in the prospecting of copper-nickel deposits in Qixin, Beishan, Xinjiang, which will provide references for further exploration of copper-nickel deposits in Beishan area, Xinjiang.©2021 China Geology Editorial Office.

Late Mesozoic and Cenozoic geodynamics of the Arctic region is discussed in the context of possible mechanisms which provide multistage cyclic transformations and transport of carbon through crust and mantle. Geodynamic processes control the abiogenic generation of hydrocarbons and the patterns of their localization. Possible mechanisms of abiotic hydrocarbon generation are explained in the context of carbon transport from subduction zones to rifts and serpentinization of ultramafic rocks in the rifts in the case of the Laptev Sea and Gakkel Ridge areas. The carbon of shallow crust origin migrates with encapsulated fragments of marine sediments which are consumed in the Pacific subduction zone where they become destroyed and transformed by different chemical and physical processes. The resulting C-species are involved in mantle convection flows and reach the continental rifts of the Laptev Sea and the Gakkel mid-ocean ridge. Thus, the hydrocarbons formed in the crust and in the mantle acquire signatures of abiotic origin. According to the authors, the scale of manifestation of abiogenic methanogenesis in the lower parts of the lithosphere and in the upper mantle is not so wide. Numerous small (mm and fractions of the mm) particles of exogenous matter and dispersed carbon pulled into the mantle can only form a stable crustal geochemical plume that propagates in the plane of movement of convective flows. Indirectly, the scale of manifestation of this process can be judged by the volumes of degassing of hydrocarbon and carbon dioxide gases, as well as hydrogen and its compounds in the rift systems of the earth’s crust, which are extremely insignificant. However, in the cold seas of the Eastern Arctic, massive emissions of bubble methane of mixed genesis were found. As shown in the literature, the range of variability of stable isotopes of carbon and 14C of methane in certain areas of discharge associated with rifting demonstrates values (anomalously heavy 13C, and young 14C) that can be considered as examples of presumably abiogenic origin. Our work is mostly theoretical and suggests further discussion and improvement of the mechanism of formation of abiogenic hydrocarbons and the processes of their transformation.

The 2018 rift eruption of Kīlauea Volcano presents a superb opportunity to decipher the underlying role of magmatic processes on the behavior and hazards of basaltic volcanoes. Here, we examine the petrogenetic history of the most MgO-rich lavas (~ 7.7–8.7 wt.%) from the voluminous (> 0.8 km3) main phase of this eruption on the volcano's lower East Rift Zone (LERZ). Our results show that these lavas are compositionally homogeneous, but distinct from recent samples of the Puʻu ʻŌʻō eruption on the middle ERZ (MERZ) and the summit lava lake within Halemaʻumaʻu pit crater. The MgO-rich 2018 LERZ lavas have relatively high K2O and TiO2 abundances at a given MgO value, high Nb/Y ratios, and low CaO/TiO2 and Sr/Zr ratios. These observations preclude a simple hypothesis that the collapse of the caldera in 2018 forced magma from the summit reservoir to erupt directly on the LERZ. Instead, the distinctive chemistry of the MgO-rich 2018 LERZ lavas supports a new model of mixing between three components: (1) olivine-controlled magma, derived from the summit reservoir via Puʻu ʻŌʻō, (2) differentiated magma similar to the earliest lavas from the 2018 rift eruption, and (3) olivine. The differentiated magma was stored within the ERZ since the 1960s. The summit-derived magma (~ 91–95%) accumulated downrift of Puʻu ʻŌʻō and mixed with the differentiated magma (~ 5–9%) over ~ 10 years prior to 2018. This process created a large (> 0.8 km3) magma body within the MERZ that was the direct source of the MgO-rich 2018 LERZ lavas. The magma that was removed from the summit reservoir during the 2018 caldera collapse (up to ~ 0.8 km3) remains within the ERZ, along with any leftover magma from the Puʻu ʻŌʻō and 2018 rift eruptions. The summit reservoir has likely been replenished with magma based on recent lava lake activity within Halemaʻumaʻu from December 2020 to May 2021. Thus, Kīlauea's plumbing system from the summit to the LERZ may now be flush with magma and primed for a new era of frequent and/or large eruptions. [ABSTRACT FROM AUTHOR]

The soil diversity of the Central ecological zone of the Lake Baikal drainage basin within the Buryat Republic has been analyzed. The soil cover is formed by 38 soil types. The compiled updated soil map of the region includes 18 soil contours of the dominating, accompanying, and occurring soil types. The area assessment of soil resources has been performed. The revealed predominating effect of the vertical zonality on the soil spatial distribution is the most pronounced in high and mid-altitude mountains. The soil cover of high mountains is dominated by poorly formed soils (lithozems and petrozems (Regosol and Leptosol)) with accompanying soils, as well as gleyzems (Gleysols) with peat-gleyzems (Histic Gleysols) and peat-lithozems (Histic Regosol). More than half of the region is occupied by soils of the mid-altitude mountains with the complicated soil cover dominated by podburs (Ferric Umbric Podzols) and burozems, as well as by podzols, soddy-podzols (Folic Podzols), soddy-podburs (Ferric Folic Umbric Podzols), etc. Low mountains are mainly occupied by podzols and gley soddy-podzols (Folic Gleyic Podzols) with accompanying soddy-podzols (Folic Podzols) and soddy-podzolic-gley soils (Folic Gleyic Retisols). Soils of mountain depressions are mainly represented by gray metamorphic soils (metamorphic Folic Umbrisols), soddy-podburs (Ferric Folic Umbric Podzols) in combination with soddy-gray soils (Folic Umbrisols), as well as by humus psammozems (Mollic Arenosol). In floodplains, estuaries, and river deltas, various complexes of alluvial soils, that is, dark humus (Umbric Fluvisols), gley dark humus (Umbric Gleyic Fluvisols), stratified alluvial (Fluvisols), soddy-gley (Folic Gleyic Fluvisols), peat-gley (Histic Gleyic Fluvisols), etc., are formed. Peat eutrophic soils (Histosols) and peat-gleyzems (Histic Gleysols), as well as peat-gley soils (Folic Gleysols) and peat-cryozems (Histic Cryosols), occur on swamp massifs. Lakesides are mainly occupied by dark-humus gley (Gleyic Phaeozems) and peat eutrophic soils (Histosols). Saline soils are practically absent in the region. [ABSTRACT FROM AUTHOR]

The properties of slow seismic activity migration have been revealed by the space-time analysis of the total earthquake energy (LgEsum). Our study of seismic activity covers the fragments of the Central Asian, Pacific and Alpine seismic belts: the Baikal rift system (BRS, Russia), the San Andreas fault zone (California, USA), the Christchurch fault (New Zealand), the North and East Anatolian faults (Turkey), the Philippine subduction zone, and the central fragment of the Mid-Atlantic oceanic ridge. The chains of LgEsum clusters mark the propagation of the maximum stresses front in the weaker crust areas, the zones of fault dynamic influence, and the regions of conjugated tectonic structures. The migration process is characterized by a periodicity, changes in direction, and similar modular values of the migration rates within a single fault segment (or a fault zone), which is probably related to the mechanical and rheological crust and upper mantle properties. The data analysis shows that a strong earthquake source may occur at a location wherein the front of seismic activity propagates with periodical changes in direction, and such a source can develop within a period that is multiple of the migration fluctuations, probably associated with the influence of external periodic factors. The main periods of migration fluctuations (2–4 years, and 9–13 years, in different ratios) are present in the seismic regimes of different seismic belts. The migration rate, as well as the propagation velocity of the maximum stresses front, directly depends on the velocity of movements between the plates in the region.

The high frequency of historical eruptions at Kīlauea Volcano presents an exceptional opportunity to address fundamental questions related to the transport, storage, and interaction of magmas within rift zones. The Nāpau Crater area on Kīlauea's East Rift Zone (ERZ) experienced nine fissure eruptions within 50 years (1961–2011). Most of the magma intruded during these frequent eruptions remained stored within the rift zone, creating a potential magma mixing depot within the ERZ. The superbly monitored and sampled 2011 eruption (Puʻu ʻŌʻō episode 59) presents an extraordinary opportunity to evaluate magma mixing processes within the ERZ. Whole-rock, glass, and olivine compositions were determined, not only for lava from the 2011 eruption, but also for a new suite of Nāpau Crater area samples from the 1963, 1965, 1968, 1983, and 1997 eruptions, as well as the previously undocumented 1922 eruption. Whole-rock XRF data revealed two geochemically distinct magma batches for episode 59: one less evolved (∼6·6 wt % MgO, 0·46 wt % K2O) than the other (∼6·2 wt % MgO, 0·58 wt % K2O). Episode 59 lava is remarkably aphyric (∼0·1 vol. % phenocrysts), making use of mineralogy to identify parent magma affinities problematic. Linear compositional trends of whole-rock major and trace elements, and reversely zoned olivine crystals indicate episode 59 lavas underwent magma mixing. Least squares regression calculations and plots of major and trace element data, were used to evaluate whether the episode 59 samples are products of mixing summit-derived magma with residual magma from previous Nāpau Crater area eruptions. The regression results and trace element ratios are inconsistent with previously proposed mixing scenarios, but they do support mixing between summit-derived magma and residual magma from the 1983 and 1997 Nāpau Crater area eruptions. These magmas were stored in physically and chemically distinct pods at depths of 1·6–3·0 km prior to mixing with new magma intruded from the summit to produce the episode 59 lava. One pod contained a fractionated equivalent of 1983 lava, and the other a hybrid of compositions similar to 1983 and 1997 lavas. The petrology of episode 59 lava demonstrates that magmas from two previous eruptions (1983 and 1997) were available to mix with magma intruded from the summit region. This study clarifies the pre-eruptive history of the mixed episode 59 lava, and elucidates the evolution of the volcano's magmatic system in a region of frequent eruptions. [ABSTRACT FROM AUTHOR]

Kīlauea is a frequently active, open-system volcano on the Island of Hawaiʻi known for erupting olivine-dominated tholeiitic basalt compositions. On rare occasions it erupts more differentiated magmas (<1% of erupted volume), such as basaltic andesites and andesites, from its rift zones. These differentiated magmas offer an opportunity to understand better the petrology, magma storage, magma mixing, and eruptive triggers that occur in Kīlauea's rift zone reservoirs. This study focuses on an eruption from the Southwest Rift Zone of Kīlauea, which is dominantly basaltic andesite with subordinate basalt. This eruption originated at the Kamakaiʻa Hills during the early 19th century and has two eruptive phases: 1) an early 'a'ā phase that is primarily exposed in the eastern part of the flow field, with minor western lobes, and 2) a late pāhoehoe phase that makes up most of the western part of the flow field. The early 'a'ā phase covers at least 5.8 km2 with an erupted volume of ∼150 × 106 m3 and consists of uniform composition basaltic andesites with 3.72–4.15 wt% MgO over its ∼7 km flow length. The late pāhoehoe phase reached >10 km from its vent, covers an area of ∼7.1 km2, has a volume of ∼100 × 106 m3, and initially erupted basaltic andesite near its vent (4.50–5.64 wt% MgO extending to 3.8 km from vent) with channel and tube-fed basalt (6.21–12.38 wt% MgO sampled at >3.8 km from vent) emplaced during its waning stages. Most Kamakaiʻa Hills lavas are crystal-poor, containing ≤1.5% glomerocrysts and individual phenocrysts of plagioclase + clinopyroxene + Fe Ti oxides ± orthopyroxene, as well as olivine in lavas with >6 wt% MgO. Major-oxide and trace-element concentrations throughout the Kamakaiʻa Hills lavas demonstrate the involvement of three distinct magmatic processes. First, the basaltic andesites of the early 'a'ā phase are the products of fractionation of plagioclase + clinopyroxene + Fe Ti oxides ± orthopyroxene, indicative of magmas that have been stored in rift zone reservoirs for decades or longer. Second, the near-vent (within ∼400 m of vent) basaltic andesites of the late pāhoehoe phase yield chemical concentrations that indicate magma mixing with a more differentiated magma (of a similar evolved composition to basaltic andesites at ∼55–56 wt% SiO 2 and ∼3.4–4.1 wt% MgO that erupted in the lower East Rift Zone in 2018). Third, the progressively more mafic magma (containing olivine + plagioclase + clinopyroxene) that continued to erupt throughout the waning stages of activity suggests an eruptive triggering process whereby an intruding summit or uprift reservoir basalt overpressurized and forced out the stored, differentiated magma of the Kamakaiʻa Hills rift zone reservoir. • The Kamakaiʻa Hills erupted a large volume of differentiated magma from Kīlauea. • This magma evolved over decades to centuries in a rift zone storage reservoir. • Dike intrusion resulted in a hydraulic plunger-type eruption trigger. • Magma mixing indicates multiple magma pods associated with the rift zone reservoir. • A similar reservoir is presumed to still be within the Southwest Rift Zone. [ABSTRACT FROM AUTHOR]

Abstract The Kilauea volcano on the Hawaii island started erupting on 3rd May 2018 after an earthquake of magnitude 5.0. The initial volcano eruption and the subsequent earthquakes resulted in the opening of new volcanic fissures, continuous lava flow at the lower east rift zone and the collapse of the summit caldera floor. All these activities continued until the 1st week of August 2018. The Small Baseline Subset (SBAS) technique is an advanced form of Differential Interferometry (DInSAR) which is capable of monitoring surface deformations with millimetre level accuracy. SBAS technique was utilised here for estimating the surface deformation on Hawaii island due to the volcanic episode. InSAR coherence technique was also utilised in this study for localised analysis at the summit and at the lower east rift zone to detect the time series deformation information and lava flow patterns. 14 interferometric datasets acquired by the ESA's Sentinel-1 C-band satellite from April 2018 to September 2018 were used in this study. The data acquired by the seismometers installed at Kilauea by Hawaii Volcano Observatory, the SWIR band of Sentinel-2 and the thermal band of Landsat-8 were used to correlate and verify the results obtained through the SBAS and InSAR coherence analysis. The combined interpretation of results obtained from all the sources gave insights about the underground magma conduit system, surface deformations, lava flow channels and the correlation between the magmatic and seismic activity happened there which are discussed in detail in this paper. Highlights • Detected subsidence at the Kilauea summit and Puu Oo crater due to magma withdrawal • Increased seismic activity at summit due to Caldera floor collapse • Open channel lava flow from fissures at Leilani Estates • Lava delta formation due to ocean entry of lava flowing through open channel • Sub-terrain magma conduit from summit reservoir to Leilani Estates [ABSTRACT FROM AUTHOR]

East Africa Rift (EAR) zone countries, such as Ethiopia, Tanzania, Kenya, and Uganda are among the least developed countries in the world. Agricultural activities are the main source of their economy and huge amounts of pesticides have been imported for decades to protect crops from damage by pests and diseases. Some of these pesticides expired in storage before they were used and their disposal became a major problem. Further, these countries declare different policies related to pesticide management. This study reviews the relevant literature about import, disposal and health impacts of pesticides together with different related policies. Web of Science, Google Scholar, and Google were used as the main sources of information. Records show the increases in the import of pesticides in Ethiopia from 2013 to 2016, in Tanzania from 2006 to 2011, in Kenya from 2008 to 2015, and in Uganda from 1980 to 2004. Disposing of obsolete pesticides is very costly and needs proper facilities. Therefore, EAR countries transport these pesticides to European countries for incineration. For example, Ethiopia disposed of 1574.5 and 926 tonnes of obsolete pesticides in collaboration with the FAO. Acute and passive pesticide poisoning occurrences are also discussed in the review. The paper also highlights the policies so far stated. However, these policies lack proper implementation. Therefore, this study suggests EAR countries should use alternative methods to protect crops from the damage caused by pests and diseases, which could reduce the excessive import of pesticides. Similarly, training should also be given to all stakeholders to ensure implementation of all policies. [ABSTRACT FROM AUTHOR]