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Artificial Neural network are commonly used for time series forecasting, especially in financial forecasting, and when external information is useful. The aim of this study is to forecast direct economic losses of Earthquake in Indonesia using NNAR and ARIMA models and selects a model that produces a forecast with a minimum root mean square error (RMSE). The accurate prediction of the direct economic losses of earthquake is critical for allowing policy makers to take a decision to anticipate losses in the future. For the purpose of forecasting accurately, an additional method is used, namely GARCH method for resolving the white noise problem in residual, such as heteroscedasticity, autocorrelation and normality. In this paper, two interpolations are applied to expand the original small sample with virtual points. The data of direct economics losses in Indonesia during the period from 1989 to 2021 were collected from EM-DAT (The International Disaster Database). The data partitioned into training and validation periods, such that the last 5 years are the validation period. The software used for ARIMA-GARCH is EViews 10 and NNAR accomplished by forecast package in R software. Based on the analysis, obtained that the result of this study is the neural network autoregression in the training period has an RMSE of 2.412, compared to ARIMA-GARCH 9,197. The neural network autoregression is significantly worse in the validation period. Its RMSE is 24,66 versus ARIMA-GARCH 8,4. According to the RMSE value, we can notice that the ARIMA-GARCH method outperform the NNAR (4,1,20) [4] model for validation period and to forecast the direct economic losses of Earthquake in Indonesia. [ABSTRACT FROM AUTHOR]

As well known, Padang is a city with a high risk for earthquake motion. Due to its functionality, Reinforced Concrete (RC) shophouse buildings are commonly constructed in this city. The strong 2009 West Sumatra earthquake resulted in several buildings being damaged, collapsing, including the RC shophouse buildings, and causing fatalities. Almost thirteen years after the earthquake, many of these types of buildings have been constructed. Unfortunately, based on field investigation and analytical studies using pushover analysis have shown that the seismic performance of the existing buildings has not enough to anticipate the damage to the structure caused by the future earthquake. Most of them fall to Damage Control (DC) and Life Safety (LS) levels, indicating that the structure of these RC buildings may damage during a strong earthquake. In this paper, a seismic safe typical structural components of shophouse construction is proposed following the current building code in Indonesia. Evaluating the seismic performance using the ATC-40 standard shows that the proposed these components RC structure is categorized to the Immediate Occupancy (IO) level. [ABSTRACT FROM AUTHOR]

GGMPlus data is a combination of GOCE and Grace Satellite Gravity data, EGM2008, and short-wavelength topographic gravity effects. This data has a resolution of∼200 m for the mainland. In this study, we used GGMPlus data to identify faults and subsurface in the Mamasa region in western Sulawesi using the gravity method. This paper discusses the result of 3-dimensional (3-D) gravity modeling for mapping subsurface structures in the Mamasa area associated with the presence of active faults. The second vertical derivative (SVD) filtering method was performed on simple Bouguer anomaly (SBA) data to obtain the straightness of the geological structure in the study area. Meanwhile, 3-D gravity modeling was carried out to obtain an overview of the continuity of fault structures in the vertical direction as a function of depth. The modeling results show that up to a depth of between 3.5 and 4 km, two blocks have a density of 1,764 g/cc and 3,189 g.cc, respectively. The utilization of satellite data from GGMPlus is very helpful in identifying active faults in Indonesia for efforts to improve earthquake disaster mitigation. [ABSTRACT FROM AUTHOR]

Indonesia as a country located on the equator often experiences disasters such as earthquakes, tsunamis, flash floods, etc. The resulting impact often cuts off the available communication infrastructure. The LAPAN-A2 satellite which has an equatorial orbit carries the payload voice repeater for amateur communications. This satellite circles the territory of Indonesia 14 times a day, therefore this payload is very useful as an alternative means of communication after a natural disaster. This paper describes the use of voice repeaters as an alternative means of communication by taking a regional study of the city of Palu. [ABSTRACT FROM AUTHOR]

Machine Learning of seismic signals is considered to automatize the analysis of years of the recorded signal. In this research, we considered using the wavelet transform based machine learning approach to analysis the spectrum signal which recorded from Broadband Seismic Network in North Tapanuli area. We use the signal seismic which recorded from GSI, MNSI, PBSI, PSI, SBSI, and TDNI which has been deployed in North Tapanuli, North Sumatera, Indonesia. The main aim of this paper to extract the different the value and spectrum of the seismic signal and identify the energy of signal of seismic which recorded from the sensor. The result shows that for all signal, which recorded form broadband seismic network information for detection and characterization is found in the instantaneous spectrum, and the makes seismic signal most useful is that this spectrum changes over time. The wavelet-based machine learning approach utilizing a complex Morlet analyzing wavelet is not only particularly suitable to clearly and simultaneously of seismic signals but also powerful for processing frequency-energy with variant signal seismic with a short period. [ABSTRACT FROM AUTHOR]

The liquefactions phenomena have been reported after a shocking 6.5Mw earthquake hit Yogyakarta province in the morning at 27 May 2006. Several researchers have reported the damage, casualties, and soil failure due to the quake, including the mapping and analyzing the liquefaction phenomena. Most of them based on SPT test. The study try to draw the liquefaction susceptibility by means the shear velocity profiling using modified Multichannel Analysis of Surface Waves (MASW). This paper is a preliminary report by using only several measured MASW points. The study built 8-channel seismic data logger with 4.5 Hz geophones for this purpose. Several different offsets used to record the high and low frequencies of surface waves. The phase-velocity diagrams were stacked in the frequency domain rather than in time domain, for a clearer and easier dispersion curve picking. All codes are implementing in Matlab. From these procedures, shear velocity profiling was collected beneath each geophone's spread. By mapping the minimum depth of shallow water table, calculating PGA with soil classification, using empirical formula for saturated soil weight from shear velocity profile, and calculating CRR and CSR at every depth, the liquefaction characteristic can be identify in every layer. From several acquired data, a liquefiable potential at some depth below water table was obtained. [ABSTRACT FROM AUTHOR]

Interferometric synthetic aperture radar (InSAR) based on radar satellite data has emerged as a powerful technology for observing the Earth's surface, especially for monitoring the Earth's topography and deformations. However, it is well known that the InSAR measurements are often significantly affected by the atmosphere. This paper applies the pairwise logic (PWL) and the Differential Interferometric Synthetic Aperture Radar (D-InSAR) technique using multitemporal SAR image from Sentinel-1A (S1A). The objective of this study was to investigate the possibility of using PWL in reducing atmospheric delay and improve the results in capturing the deformation signal from the artifact. We stacked twelve pairs of S1A data before and after the December 6, 2016, Mw 6.5 Pidie Jaya earthquake in Aceh, Indonesia. Multitemporal interferograms of S1A in ascending and descending orbits were used to obtain Line of Sight (LOS) motion maps. To generate the differential interferogram of the PWL, then the first and the second interferogram were computed by summation process. Next, the second interferogram was added with the third, until the last interferogram of D-InSAR data pairs. The final data pair summation produced six pairwise interferogram. The results indicated that the summation of interferogram can increase the deformation twice in the line of sight of the satellite which represents movement toward or away from the satellite (e.g. uplift or subsidence), and also eliminated positive and negative signals in the line of sight velocities, which represent the atmospheric phase delay. The PWL simplified the complexity of atmospheric correction in the D-InSAR processing by reducing atmospheric artifact and increasing the deformation signal. [ABSTRACT FROM AUTHOR]

Geographical factor and high population density causing the area of Kelurahan Cigadung (RW09 and RW14), Bandung City, Indonesia becoming prone to disaster events. As such, narrow pathways and congested housing settlements to amplify complexity in determining evacuation routes in the events of disaster. Additionally, limited availability of open spaces for assembly point during disaster evacuation process could worsen disaster impact among the community. Thus, disaster preparedness (knowledge) and disaster risk reduction (DRR) awareness within community is vital to minimize disaster impacts. The objective of this paper is to establish disaster risk reduction through community participation in disaster events. A three weeks of data collection was conducted in the form of literature review, workshops and interview sessions. Participatory Disaster Risk Assessment (PDRA) criteria were used to establish community participation on disaster risk reduction within the community. The criteria includes preparation; hazard assessment (disaster history and transect walk); capacity and vulnerability assessment (people daily activities, household and community analysis); key informant interviews (chief of RW and Chief of RTs); and action planning. The qualitative data where then analyzed using Atlas.ti Version 8.0. Findings revealed that there are three types of disaster, (1) earthquake, (2) landslide and (3) flood which are potentially to occur in the area. The outcomes of the research is to enhance community in being resilience towards disaster events in future. This is inspired by Sendai Framework for Disaster Risk Reduction 2015 - 2030: Priority 3 - Investing in Disaster Risk Reduction for Resilience. [ABSTRACT FROM AUTHOR]

Fault is one of the dangerous earthquake sources that can cause building failure. A lot of buildings were collapsed caused by Yogyakarta (2006) and Pidie (2016) fault source earthquakes with maximum magnitude 6.4 Mw. Following the research conducted by Team for Revision of Seismic Hazard Maps of Indonesia 2010 and 2016, Lasem, Demak and Semarang faults are three closest earthquake sources surrounding Semarang. The ground motion from those three earthquake sources should be taken into account for structural design and evaluation. Most of tall buildings, with minimum 40 meter high, in Semarang were designed and constructed following the 2002 and 2012 Indonesian Seismic Code. This paper presents the result of sensitivity analysis research with emphasis on the prediction of deformation and inter-story drift of existing tall building within the city against fault earthquakes. The analysis was performed by conducting dynamic structural analysis of 8 (eight) tall buildings using modified acceleration time histories. The modified acceleration time histories were calculated for three fault earthquakes with magnitude from 6 Mw to 7 Mw. The modified acceleration time histories were implemented due to inadequate time histories data caused by those three fault earthquakes. Sensitivity analysis of building against earthquake can be predicted by evaluating surface response spectra calculated using seismic code and surface response spectra calculated from acceleration time histories from a specific earthquake event. If surface response spectra calculated using seismic code is greater than surface response spectra calculated from acceleration time histories the structure will stable enough to resist the earthquake force. [ABSTRACT FROM AUTHOR]

The research aims to investigate students' collaborative problem solving skills (CPS) through constructed interactive animation. The research was carried out in Public Junior High School in Bandung Indonesia. The number of participant was 39 of samples of 8th grade, Junior High School students. The method used in this research was descriptive. The paper provides the result of observation of students' CPS in 11aspects, they are: 1) Discovering perspectives and abilities of team members, 2) Discovering the type of collaborative interaction required and establishing goals, 3) understanding roles to solve problem, 4) building a shared representation and negotiating the meaning of the problem (common ground), 5) Identifying and describing tasks to be completed, 6) Communicating with team members about the actions performed, 7) enacting plans, 8) following roles of engagement, 9) monitoring and repairing the shared understanding, 10) monitoring results of action and evaluating success in solving the problem, 11) Monitoring, providing feedback and adapting the team organization and roles. The result of study indicated that students were good in doing communication with team member (aspect 6) which showed by their achieved highest of this aspect. On the other hand they need to improve their monitoring, providing feedback, and adapting the team organization and roles ability (aspect 11), as the score of this aspect is the lowest. The result of study supported that the software is capable to measure students' CPS skills. [ABSTRACT FROM AUTHOR]

In the past few years, Earthquakes have struck Indonesia several times, which caused many people to lost their lives. Every day, the Indonesian Meteorological, Climatological, and Geophysical Agency (BMKG) is responsible to monitor the seismic activity through several stations located around the country and record them as waveform including any Earthquake that occurs and determine their magnitude respectively. The aim of this study is to collect those waveform raw data from BMKG and able to utilize several tools to convert and process the data for further research purposes. One of the purposes is to compare the waveform data with the determined magnitude and to find the relationship between them. This paper served as a discussion in seismology and a better understanding of the Earthquake. [ABSTRACT FROM AUTHOR]

Indonesia is known as an earthquake-prone area so it requires a lot of research on earthquakes. With the increasing number of studies, the risk due to earthquakes can be better understood and mapped, especially the risk of damage to important structures in the road network system such as bridges. This study is aimed to acknowledge the behaviour of a concrete bridge due to different types of earthquakes, in accordance of dynamic displacements in the top piers of the bridge. The bridge used to be analyzed is five spans bridge, located in Batuceper – Kunciran (CBK Toll Road) in the Tangerang area. The configuration of the bridge is simple span structure system, multiple superstructure spans and single pillar columns with circular cross section. Earthquake loads applied to the bridge in the form of ground motion from the Mentawai Earthquake, El-Centro Earthquake, Lampung Earthquake, and Tangerang Earthquake. Results show that the pattern and the symmetric of the structure affect the patterns of the dynamic displacements of the top piers of the bridge. [ABSTRACT FROM AUTHOR]

Research on seismic, microzonation of Semarang is still ongoing. Following the research conducted by Team for Revision of Hazard Maps of Indonesia 2010, Lasem fault was the only fault that should be taken into account for seismic mitigation of Semarang. New research conducted by Team for Updating of Seismic Hazard Maps of Indonesia 2016 suggesting four new and closest shallow crustal fault sources (Rawapening, Weleri, Demak and Semarang Faults) which should be taken into account for seismic hazard mitigation of this city. Those four new seismic sources are typical reverse mechanism seismic sources. However Lasem fault is a typical strike slip mechanism seismic source. This paper presents the development of surface acceleration time histories due to three shallow crustal fault (Lasem, Semarang and Demak) earthquake sources with average magnitude 6.5 Mw. This research was performed by implementing deaggregation hazard analysis, response spectral matching and site response analysis to obtain modified acceleration time histories. The modified acceleration time histories were developed due to inadequate data caused by those three fault sources. Surface acceleration time histories were calculated at 288 boring locations and then separated into three different time histories based on site class soil conditions (hard, medium and soft soil classes). [ABSTRACT FROM AUTHOR]

As as the Capital of West Sumatera Province and as the largest city at the West Coast of Sumatera, the City of Padang has been assigned as one of the National Activity Center for Regional Economic Development. The city will be developed as a metropolitan city, which will be very much relied on the multi sectoral support such as business, services, industry, and tourism sectors. However, the city is located at a very high-risk zone for earthquake and tsunami. After 2004 Indian Ocean Tsunami, the city lias been stricken several times by large earthquake and tsunami threat, for example in 8.4 M September 2007 and 7.6 M September 2009 causing major casualties, severe damages, great economic loss as well as tsunami threat to the people. Without disaster risk reduction based development planning, the goal of Padang as metropolitan and National Activity Center is difficult to be achieved. Knowing the level of risk and its appropriate countermeasures from the perspective of business resilience becomes very important. Thus, this paper will present the detail study on business rehency for the Padang City, starting from (i) Earthquake and Tsunami Risk Assessment from the perspective of preparedness for Business in Padang Barat Subdistrict of Padang City, (ii) Assessment of resiliency level of Padang City Business after the 2009 event, and (iii) recommendation for considering the Business Resilience factors as part of DRR based CBD development Plan of Padang Barat sub district - Padang City. This study is not only able to identify physical and nonphusical aspect of business characteristic, but it has identified four major components of Bussiness Resiliency Indicators, i.e. Swift Recovery Factors (RR), Experience and Knowledge to Disaster (PP), Emergency Response Plan (RT) and Asset Protection (PA). Each major indicator consists of several indicators, with 19 total indicators. Further investigation on these indicators shown that total performance value of business resiliency is 65,36%, which means that Small, Micro and Medium Business in Padang City are resilient toward earthquake and tsunami. Some indicators show their performance value below minimum limit of 55%. Such as 48.84% for Knowledge and Experience to Disaster (PP) which comprised of several low knowledge and low preparedness among business, has led to the need for an intensive and extensive public education program for business community. While the low performance value of Assett Protection indicators has been influenced by the low performance value of insurance, i.e. 42,22% below minimum limit, meamng that a government intervention to promote risk transfer mechanism via insurance is needed. Among the four major components of Bussiness Resiliency Indicators, the component of Asset Protection Indicators (PA) shows the strongest correlation with non-physical aspects of business characteristic, i.e. the length of business and omzet. The performance value of the 19 Business Resiliency factors and its correlation with physical and nonphysical business characteristics are very important to be considered in improvmg CBD development plan as part of city zoning m order to achieved a resilience central business districts (CBD). [ABSTRACT FROM AUTHOR]

An earthquake is a big disaster that might cause a large amount of loss. Various ways had been proposed to overcome this situation, including the usage of catastrophe bonds. In this study, we propose an earthquake catastrophe bond in which both the coupon payment and principal payment are affected by the occurrence of earthquakes during the period. The pricing of this bond consists of several steps as follows: (1) obtain the earthquake data, (2) model the probability distribution of earthquake magnitude and depth, (3) propose the catastrophe bond's payment structure, and (4) derive the price formula. A numerical study using the data of earthquakes around Java and Sulawesi, Indonesia, is provided. We find that these data can be modeled well using Generalized Extreme Value (GEV) distribution, Rayleigh distribution, and Generalized Pareto distribution. Consequently, the price of catastrophe bonds can be determined using these distribution. [ABSTRACT FROM AUTHOR]

Indonesia is a country that is often hit by tectonic earthquakes. This is because Indonesia is located at the confluence of three of the world's significant plates. One of the areas in Indonesia that were hit by a tectonic earthquake is the island of Lombok. The last tectonic earthquake that was destructive and caused many victims was in 2018. In this study, measurements were made of the distance between tectonic earthquakes and Selong City, the capital of East Lombok Regency. The distance measurement results were divided into three groups, and the distribution type was determined using the Kolmogorov-Smirnov test approach. The results of this study can be used as a reference in the revision of regional spatial planning and disaster mitigation by the provincial government of West Nusa Tenggara Province, especially the Regency/City on the island of Lombok. [ABSTRACT FROM AUTHOR]

Earthquakes are one of the most destructive natural disasters on earth, which are the result of surging tectonic stress, and it extremely difficult to predict due to a lack of different statistical patterns required to model future occurrences. Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) said that there were 11.920 earthquakes happen in 2018 and 11.473 earthquakes in 2019. In 2018, there were 29 destructive earthquakes and one earthquake followed by a tsunami that caused 4047 people dead or lost, 6.439 people injured, 704.849 people evacuated, and thousand public facilities damage. While in 2019, there were 147 people injured, 5.025 homes damaged, and a hundred public facilities damage caused by 13 destructive earthquakes. Earthquakes prediction is necessary to reduce the risk caused by earthquakes. The purpose of this research was to predict when the earthquake would happen from the instrumentation system based on the telemonitoring of radon concentration anomaly to provide an early warning system alarm before an earthquake occurs. The methodology used in this research was built radon concentration monitoring systems that were placed near the fault around Yogyakarta-Indonesia. Radon concentration is measured every hour. Then, the author analyzed the correlation between radon gas concentration and the earthquakes happen from Sumatra until NTT. The data of earthquakes were taken from the Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) and Postdam Geofon. After measuring the radon gas concentration for 9 months and doing analysis, it was found that the prediction of an earthquake could be decided when 4 of 5 algorithms were confirmed. Based on the algorithm that was determined, there were 34 of 51 earthquakes that were successfully predicted and 34 of 66 true algorithms. So, the correctness of the prediction is 51,52% with an accuracy of 66,67% that the earthquake will happen 1 until 3 days later. [ABSTRACT FROM AUTHOR]

A strong earthquake with a moment magnitude of 9.0 on year 2004, 8.7 on 2005 and 8.4 on 2007 that hit Sumatra had elicited sinkhole incidences in limestone karst bedrock. A study was carried out in Kampar, Perak where the area had sinkhole hazards due to the tremors. The site location is underlain by limestone formation, suspected to have numerous cavities which is prone to risk of sinkhole occurrences. The objective of this study is to determine the characteristics of the limestone residual soil in the karst terrain. A non-invasive site investigation by using geoelectrical resistivity was conducted. The soil investigation reports on the same site were analyzed to correlate to the physical properties and strength of these residual soils. The physical classification test on soil samples were carried out to determine the bulk and dry density, moisture content, particle size distribution, particle density, liquid and plastic limit for characterization. The approach of indirect data analysis is to study the reliability of the geoelectrical resistivity value to the soil properties and soil strength, hence deduce the most vulnerable sinkhole prone residual soil material. [ABSTRACT FROM AUTHOR]

North Sulawesi Trench or Minahasa subduction area is a subduction zone between the oceanic crust of Sulawesi Sea and the North Sulawesi Arm located at the triple junction in Eastern Indonesia. This subduction activity causes the North Arm of Sulawesi as an earthquake-prone area. Tectonic activities in the region can be studied through geodetic monitoring using GNSS GPS observations and by physical modelling from the rate of geodetic geometric results. Yearly GNSS GPS campaign have been conducted in the region from 1997 to 2008 and continuously observed by BIG from 2008 to 2016 using permanent GNSS GPS stasion. The coordinates of monitoring stations realized in ITRF-2008 provide residual RMS values of 3.13 mm, 4.15 mm and 7.26 mm for the northern, eastern and vertical components, where this indicates a high degree of accuracy. A simple estimation profile using GNSS GPS data based on the Okada elastic equation for the subduction zone shows a subduction movement ranging from 4 to 5 cm/yr with a locking depth of about 50 km, a dip 300 and ending in the post-seismic phase due to the sequence of earthquakes occurring in Minahasa since January 1, 1996 Mw 7.9 to 16 June 2002 Mw 5.9. [ABSTRACT FROM AUTHOR]

The FORMOSAT-3 / COSMIC satellite with GPSRO technique was performed to detect an earthquake in the presence of fluctuations in the ionosphere layer. This research was used to know the change of TEC in ionosphere layer during earthquake. FORMOSAT-3 / COSMIC was a microsatellite that aims for weather and climate assessment, and atmospheric, ionospheric and geodesy observations. FORMOSAT-3 / COSMIC was a Taiwan-USA collaboration by launching 6 microsatelt on LEO (Low Earth Orbit). Each of these FORMOSAT-3 / COSMIC satellites has a payload: GPS Occultation Experiment (GOX), Tiny Ionospheric Photometer (TIP) and Tri-band Beacon (TBB). GOX consists of a GPS receiver, the highest rated occultation antenna and Precise Orbit Determination (POD) antenna to collect data from Radio Occultation (RO) observations and precision orbits. RO is obtained from GPS orbit and different FORMOSAT-3 / COSMIC (LEO) orbit causing fluctuation when transmitting signal. This variation contains ion component called Total Electron Content (TEC). The earthquake of March 2nd, 2016 west Sumatra was a strike slip earthquake which had magnitude 7.7 Mw with tsunami potential. In this earthquake detected an ionospheric disturbance of 3.5 TECU after the earthquake. [ABSTRACT FROM AUTHOR]

Gede Volcano (West Java, Indonesia), is located 60 km southern of Jakarta with altitude of 2,598 m above the sea level. This stratovolcano is categorized into type A volcano (magmatic eruptions after 17th century) and within one of the regions with the highest population density in the world. The characteristic eruptions occurred in Gede Volcano are commonly small and short in period. Almost every year, the seismicity of Gede Volcano significantly increased and was dominated with volcano-tectonic A-type event, volcano-tectonic B-type event, tectonic event, and tremor. The last swarm occurred in February-March 2012, was caused by the tectonic movement of the fault and intrusion. The objective of this study is to determine the low velocity zone due to the hot materials or weak zone. We picked manually the arrival times of P wave and S wave for the volcano tectonic events and local tectonic events of January 2016-January 2017 period. Most of the hypocenters are having a fix depth solution, due to the azimuthal GAP higher than 180o. We also found a cluster event between Gede Volcano and Pangrango Volcano at depth of 0 until 28.47 km under the mean sea level. Then the 1-D velocity model was updated and the hypocenters were relocated with VELEST33. The relocated hypocenters were getting closer to the volcano area, and the hypocenter with fix depth solution has been reduced. The updated velocity model, origin time, and hypocenter location were used as input to get the 3-D velocity model of P wave, S wave, and Vp/Vs ratio. We evaluated the resolution model by applying the checkerboard test and derivative weight sum, however, we acknowledge for the checkerboard tes did not show a fairly good recovery due to insufficient resolution in our study. The tomographic results show some prominent features as follows (i) high Vp anomaly and lowVp/Vs anomaly are observed at depths of about -2 km to -1 km which may be related to altered zone, (ii) high Vp anomaly and low Vp/Vs anomaly at depths of about -2.5 km to 2 km which may be associated with hot material, and (iii) low Vp anomali and high Vp/Vs at depths of 0 - 2 km which may be interpeted as weak zone (fractured zone). [ABSTRACT FROM AUTHOR]

West Sumatra is vulnerable to earthquakes and tsunami as it is located in the fault zone and the subduction zone between the Eurasian plate and the Indo-Australian plate spread from northern Sumatra to the southern island of Java, NTB, Sulawesi to Papua. This subduction zone affects the earthquake potential with shallow epicentrums even potentially causing tsunami. The purpose of this research is to analyze and map the potential earthquake area that can cause tsunami around subduction zone by using satellite image processing method with software GFZ data analysis. Based on the results of research and data processing obtained from BMKG and data analysis from GFZ, since the period of 2007 until 2017 there is often an earthquake with magnitude over 7.0 SR, with that magnitude it is estimated that tsunami disaster may occur. However, from the several earthquakes that occur, it can be concluded that the potential for the tsunami is quite small because it does not relevant with the classification of the occurrence of tsunami based on BMKG in 2012. As the result, the research can be used to conduct disaster mitigation against earthquake and tsunami in west Sumatra. [ABSTRACT FROM AUTHOR]

Many aspects of earthquake mechanics remain an enigma, e.g.: earthquake interaction and seismic hazard mitigation. One potential bright spot is the finding that simple calculations of stress changes may explain some earthquake occurrences and interactions. This progress is especially lead by abundant studies of stress changes of humaninduced seismicity. This work introduces stress triggers, stress shadows, and their implications for seismic hazard in Indonesia. We review our work on stress analysis of the 2016 Aceh earthquake and present a compilation of quantitative earthquake interaction studies from a stress change perspective. The 2016 earthquakes were deadly, caused more than 100 causalities, and unpredicted, in a sense that the driving force and the source mechanism remain unclear. No information was present on the extent of the faulting or the direction of propagation of the event. Therefore, it requires a stress transfer modeling in order to understand the possible seismic hazard distribution. The results of this study provide some clues about certain aspects of earthquake mechanics. It also demonstrates that we still have a lot of work ahead of us before we can understand the complete mechanism of how an earthquake occurs. [ABSTRACT FROM AUTHOR]

In seismology, earth's subsurface imaging is usually use earthquake or explosive as its main sources. Ambient noise tomography is a relatively new technique to image velocity variations from natural vibrations of Earth. In this study, ambient noise tomography method is applied to Opak River Fault region, Yogyakarta, Indonesia. The fault existence was previously assumed as the source of Yogyakarta earthquake on 27 May 2006 which make it interesting to be further investigated. This research uses temporary seismometer array managed by Geo Forschungs Zentrum (GFZ) and consists of 12 stations for three months recordings (June, 1st to August, 31st 2006). Interstation Green's function is calculated using crosscorrelation process of two records data. Then, group velocity curve is determined by Multiple Filtering Technique (MFT). The set of interstation group velocity curve are then used to create group velocity maps as a function of periods. The obtained maps show velocity contrast variations in the research area ranging from 0.4 - 2.3 km/s. The Opak River Fault is clearly indicated by velocity contrast in the western part of the research area. There is also a velocity contrast that indicated the existence of another fault located ±11 km distance eastward of Opak River Fault. This fault is possibly associated with the source of Yogyakarta earthquake on 27 May 2006. [ABSTRACT FROM AUTHOR]

Deep Mill Level Zone (DMLZ) is an underground mine operation by PT.Freeport Indonesia in West Papua Province that using block caving as its mining method and it is important to use the microseismic sensor as the monitoring device for the worker's safety. The data collected on this research was from DMLZ area on level 2400-2800 mdpl where there are 32 times earthquake which has a high possibility to create severe damage on the underground mining operation. By Applicating the focal mechanism, the source mechanism that happen on the earthquake, the direction of the earthquake and also the cause of the event can be determined. From those 32 events, double couple (DC) mechanism dominated the focal mechanism type on this area, but the highest possibility to create damage on this area showed by the compensated linear vector dipole (CLVD) type which created a severe damage on the area. [ABSTRACT FROM AUTHOR]

The PGA (Peak Ground Acceleration) estimation is the essential parameter in Seismic Hazard Assessments (SHA). PSHA (Probabilistic SHA) relies on generalized attenuation equation which contains uncertainty for estimation of PGA. A sophisticated method, NDSHA (Noe-Deterministic SHA) procedure has advantages in determination of PGA from realistic model of synthetic accelerogram from source-specific properties and cooperates with the structural model of sites. At the regional scale, calculation of PGA is based on one-dimensional modal summation technique. We validated the synthetic accelerogram with observations during the M 6.5 Pidie Jaya earthquake on December 7th, 2016. Those observational accelerograms data were recorded by two stations of three-channel accelerometers deployed by BMKG, namely KCSI and LASI. Based on recorded data of the stations, evidently, the synthetics accelerogram has been well verified at the KCSI station which is located on bedrock area and less suitable for the LASI station which is located on thick sediment region. The modal summation technique is not suitable for the area located on thick sediment layer because the amplification effect which works in two-dimensional regime cannot be handle by the one-dimensional approach. Two or three-dimensional approach should be applied to the sedimentary layer at a local scale NDSHA in order to compute the amplification effect. [ABSTRACT FROM AUTHOR]

In this research, we observed Coseismic Ionospheric Disturbances (CID) of West Sumatra March 2nd, 2016 earthquake with GNSS-TEC. This earthquake had strike slip focal mechanism with earthquake moment magnitude 7.8 Mw. In order to observe ionospheric fluctuations, some GNSS stations owned by Geospatial Information Agency (BIG) were used, these stations were spread in Sumatera Island (CAIR, CBKT, CPAR, CPDG, and CSEL stations). The epoch of the GNSS Stations were 15 seconds which included GLONASS, GALILEO and GPS satellites. The CID analysis showed TEC anomalies at 11 to 15 minutes after the earthquake with magnitude 2 - 3.5 TECU. It was recorded by GPS satellites number 17 and GLONASS satellite number 14. The fluctuation of signal propagation velocity was about 0.98 km/s as acoustic wave which was calculated using peak to peak of the disturbance signal. Distance of CID signal could be observed around 600 km from epicenter with south-west location. Earthquake early warning system could not be observed in term preseismic ionospheric disturbances but appeared on seven days before the earthquake, which ionospheric anomalies was calculated using statistically method. Meanwhile, tsunami warning could be done using CID method if arrival time of tsunami is more than 15 minutes to coastline. [ABSTRACT FROM AUTHOR]

The tectonic condition of the Sulawesi Island is formed as a result of convergent and transform motion. Earthquake event with magnitude M 7.0 in Sulawesi region rarely happen, only earthquake with magnitude above M 5.0 which often. Required more identification of fracture plane of earthquakes with magnitude above M 5.0. The object of this study is to identify the area of activated fracture in the Sulawesi region from the earthquake focal mechanism data. Determination of activated fracture plane using HC-plot method, that is determination method of hypocenter location estimation to centroid. Using earthquake catalog data from BMKG, USGS, and GFZ. The earthquake data which used in this methode is data with magnitude M> 5.0 span of time in 2016 in Sulawesi region. The parameters which used in this study are hypocenter, centroid, dip and strike of each earthquake. The centroid, dip and strike parameters are obtained from Global CMT seismic network. The number of earthquake with magnitude more than 5.0 as much as 4 events are Gorontalo earthquake M 5.4, Bolangmongondo earthquake M 5.1, Palu earthquake M 5.3, and Bitung earthquake M 5.8. From the result of data processing obtained by distance of hypocenter to centroid every quake respectively from 14.23 km, 17.65 km, 4.48 km, and 24.34 km. In addition to the distance of the hypocenter to centroid also obtained a distance hypocenter to nodal plane 1 and nodal plane 2. The distance from hypocenter to nodal plane 1 each earthquake in a row is 3.09 km, 10.79 km, 3.53 km, and 16.02 km. Same as for the hyposenter distance to the nodal plane 2 of each quake respectively is 6.92 km, 6.97 km, 3.58 km, and 15.60 km. Comparison using three catalogs indicate that the hypochenter distance that almost coincides in one of the nodal planes is the fractured plane activated during an earthquake. [ABSTRACT FROM AUTHOR]

The existence of which is traversed by world plate meeting brings Indonesia in earthquake prone area. One of the dangers that occur in earthquake is soil liquefaction. At the time of the earthquake occurs, the soil changes the nature of solid into liquid due to the received cyclic load. As a result, the non-cohesive soil will lose its power. The consequence of soil liquefaction is the decline of the building. Measurement of soil strength and identification of soil type can be done by using the Cone Penetration Test (CPT). In this study, CPT measurement was used to evaluate the liquefaction potential of Puger coastal area, Jember Regency. The potential of liquefaction is determined by obtaining the value of Cyclic Resistance Ratio (CRR), Cyclic Stress Ratio (CSR), Safe Factor (SF) and subsequently calculating ground settlement due to soil liquefaction. As for the results of measurements on 13 points, 7 points of them have the potential for soil liquefaction. From those points, the largest ground settlement is up to 3.24 cm, hence based on the degree of damage to buildings developed by Ishihara and Yosimine [1], the category is included as minor damage. [ABSTRACT FROM AUTHOR]

Jumoyo Bridge is one of bridges connecting the main highways of Magelang-Yogyakarta, Indonesia. The bridge durability test was conducted to determine self-frequency and motion direction of the bridge's particles. Measurements were performed in two circumstances, namely when the location was crowded and deserted to be passed by vehicles. Measurements points consisted of six points along Jumoyo Bridge, and one point above the ground level near the bridge. Obtaining the movement of particles and HVSR spectrum, the data analysis was conducted by using Geopsy software. The self-frequency values of the bridge were calculated based on HVSR spectrum. The process of selecting signal (windowing) was performed manually on the ambient signals. The self-frequency values of the bridge obtained were in the range of 2.74 to 2.95 Hz, with the amplitude were 0.48 to 1.63 mm. The bridge's particle motion in vertical direction have trending N-S, while in horizontal direction tends to SW-NE. The ground's frequency value around the bridge was 0.79 Hz. Based on these results, it can be said that Jumoyo Bridge has resistance towards the resonance danger of the ground. For the next measurement, it needs to measure the stresses that occur to obtain more complete analysis. [ABSTRACT FROM AUTHOR]

Along the southern coast of East Java Indonesia, at a number of localities, it can be identified and attempted to assign the age of tsunami deposit. Laboratory analyses were conducted also to support this study such as Granulometry, Paleontology and radiometric dating analysis. The presence of tsunami 1994 deposit in the area of Pancer, Lampon, Prigi and Grajagan was found, as a result of 7.8 Magnitude Banyuwangi Earthquake. The radiometric dating analysis also identified some paleotsunami deposit of about 1921 and 1930 in the area of Prigi and Teleng. This paleotsunami is assumed to have a correlation with an earthquake in the south of Java at the same time. An outcrop in the Prigi and Teleng strongly convinced the fact of an earthquake generated tsunami in the south of Java in the year of about 1921 and 1930. [ABSTRACT FROM AUTHOR]

In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ?? 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green's function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake. [ABSTRACT FROM AUTHOR]

Bali, Sumbawa, and Lombok regions are located in active tectonic influence by Indo-Australia plate subducts beneath Sunda plate in southern part and local back-arc thrust in northern part the region. Some active volcanoes also lie from eastern part of Java, Bali, Lombok and Sumbawa regions. Previous studies have conducted subsurface seismic velocity imaging using regional and global earthquake data around the region. In this study, we used P-arrival time from local earthquake networks compiled by MCGA, Indonesia within time periods of 2009 up to 2013 to determine seismic velocity structure and simultaneously hypocenter adjustment by applying seismic tomography inversion method. For the tomographic inversion procedure, we started from 1-D initial velocity structure. We evaluated the resolution of tomography inversion results through checkerboard test and calculating derivative weigh sum. The preliminary results of tomography inversion show fairly clearly high seismic velocity subducting Indo-Australian and low velocity anomaly around volcano regions. The relocated hypocenters seem to cluster around the local fault system such as back-arc thrust fault in northern part of the region and around local fault in Sumbawa regions. Our local earthquake tomography results demonstrated consistent with previous studies and improved the resolution. For future works, we will determine S-wave velocity structure using S-wave arrival time to enhance our understanding of geological processes and for much better interpretation. [ABSTRACT FROM AUTHOR]

The 11 April 2012 earthquakes off-shore Aceh-North Sumatra are unique events for the history of Indonesian earthquake. It is unique because that they have similar magnitude, 8.5 Mw and 8.1 Mw; close to epicenter distance, similar strike-slip focal mechanism, and occuring in outer rise area. The purposes of this research are: (1) comparing area of earthquakes base on models and that of calculation, (2) fitting the shape and the area of earthquake rupture zones, (3) analyzing the relationship between rupture area and magnitude of the earthquakes. Rupture area of the earthquake fault are determined by using 4 different formulas, i.e. Utsu and Seki (1954), Wells and Coppersmith (1994), Ellsworth (2003), and Christophersen and Smith (2000). The earthquakes aftershock parameters are taken from PGN (PusatGempabumiNasional or National Earthquake Information Center) of BMKG (Indonesia Agency Meteorology Climatology and Geophysics). The aftershock epicenters are plotted by GMT's software. After that, ellipse and rectangular models of aftershock spreading are made. The results show that: (1) rupture areas were calculated using magnitude relationship which are larger than the the aftershock distributions model, (2) the best fitting model for that earthquake aftershock distribution is rectangular associated with Utsu and Seki (1954) formula, (3) the larger the magnitude of the earthquake, the larger area of the fault. [ABSTRACT FROM AUTHOR]

Preliminary deformation model for the Indonesia's National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault's segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except in the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year. [ABSTRACT FROM AUTHOR]

Indonesian archipelago region is located in active tectonic setting and high seismicity zone. During the last decade, Indonesian was experienced with destructive major earthquakes causing damage and victims. The information of precise earthquake location parameters are very important in partular for earthquake early warning to the society and for advance seismic studies. In this study, we attempted to improve hypocenter location compiled by BMKG for time periods of April, 2009 up to June, 2014 for about 22,000 earthquake events around Indonesian region. For the firts time, we applied teleseismic double-difference relocation algorithm (teletomoDD) to improve hypocenter region in Indonesia region combining regional and teleseismic stations. Hypocenter relocation was performed utilizing local, regional, and teleseismic P-wave arrival time data. Our relocation result show that travel-time RMS errors were greatly reduced compared to the BMKG catalog. Seismicity at shallower depth (less than 50 km) shows significantly improvement especially in depth, and refined shallow geological structures, e.g. trench and major strike slip faults. Clustered seismicity is also detected beneath volcanic region, and probably related volcano activities and also major faults nearby. In the Sunda arc region, seismicity at shallower depth centered at two major distributions parallel to the trench strike direction, i.e. around fore-arc and in mainland that related to major fault, e.g. the Sumatran fault, and volcanic fronts. Below Central Java region, relocated hypocenter result showed double seismic zone pattern. A seismic gap is detected around the Sunda-Banda transition zone where transition between oceanic subduction to continental crust collision of Australian plate occurs. In Eastern Indonesia region, shallow earthquakes are observed related to major strike slip faults, e.g. Sorong and Palu-Koro fault, volcanism, and shallow part of subduction and collision zones. We also compare our result in the Sunda Arc region with slab1.0 model and our relocated seismicity shows good agreement with the previous slab geometry. Horizontal position shift of relocated events are mostly perpendicular to the trench directions. [ABSTRACT FROM AUTHOR]

The 25 October 2010 Mentawai earthquake has magnitude Mw 7.7 and shallow depth (12 km). Although the local people of Sikakap - the closed island near epicenter (78.33 km) only felt low shaking (II-III Mercally Intensity), it rised tsunami 7.4 m height causing casualties 447 people died. We suggested the phenomenon is the tsunami earthquake. Therefore we calculate the source mechanism by using W-phase method to determine its parameter. The result yield good value due to reference of GCMT solution with strike 340.3°, dip 8.3°, and slip 116.9°. The cross section diagram of hypocenter show the event located on the beginning of subduction. We obtain the values of seismic radiated energy 1.76×1014 Nm, seismic moment 5.37×1027 Nm, and its ratio is Θ = -6.1. It counted as the threshold of tsunami earthquake. The rupture process has long duration 82 s. The facts proved that the 2010 Mentawai as a tsunami earthquake. [ABSTRACT FROM AUTHOR]