scholarly journals Use of Borehole Seismometers in Earthquake Monitoring at the Baribis Fault Leading to Jakarta, Western Java

2020 ◽  
Author(s):  
Ruben Damanik ◽  
Sri Widiyantoro ◽  
Pepen Supendi ◽  
Yayan M. Husni ◽  
Z. Zulfakriza ◽  
...  
Keyword(s):  
Active Faults ◽  
Focal Mechanism Solution ◽  
Location Determination ◽  
Fault Type ◽  
Australian Plate ◽  
Seismic Experiment ◽  
Surrounding Areas ◽  
Borehole Seismic ◽  
Plate Subduction

Abstract The region of Jakarta and its vicinity is one of the least understood geological domains in Java Island, Indonesia. Yet, the region is one of the few places which are often impacted by earthquakes from the Indo-Australian Plate subduction zone as well as on land active faults. In this study, a borehole seismic experiment was designed to unravel the seismic activity of the Baribis Fault, which continues and leads to Jakarta. This passive source experiment was composed of seven broadband instruments that extended across the Jakarta region and surrounding areas. The experiment recorded seismic data from the end of July 2019 to August 2020. We located 91 events of hypocenter location determination of the data recording; one event was located closely to the Baribis Fault line that continues to Jakarta and was felt in Bekasi (Southeast of Jakarta) at up to II-III on the Modified Mercalli Intensity (MMI) scale. The focal mechanism solution of this event shows an oblique thrust fault type. This event is evidence that the Baribis Fault is active.

scholarly journals Earthquake monitoring of the Baribis Fault near Jakarta, Indonesia, using borehole seismometers

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ruben Damanik ◽  
Pepen Supendi ◽  
Sri Widiyantoro ◽  
Nicholas Rawlinson ◽  
A. Ardianto ◽  
...  
Keyword(s):  
Active Faults ◽  
Primary Objective ◽  
Low Noise ◽  
Fault Line ◽  
Focal Mechanism Solutions ◽  
Noise Characteristics ◽  
Nearest Point ◽  
Seismic Experiment ◽  
Borehole Seismic ◽  
Good Agreement

AbstractThe geological setting of Jakarta and its immediate surroundings are poorly understood, yet it is one of the few places in Indonesia that is impacted by earthquakes from both the Java subduction zone and active faults on land. In this study, a borehole seismic experiment with low noise characteristics was deployed to record seismic activity on the ~ E-W oriented Baribis Fault, which is ~ 130 km long, passes to the south of Jakarta, and is only ~ 20 km away at its nearest point. A primary objective of this study is to determine whether this fault is seismically active, and therefore, whether it might pose a threat to nearby population centers, including Jakarta in particular. A total of seven broadband instruments that spanned Jakarta and the surrounding region were installed between the end of July 2019 and August 2020, during which time we were able to detect and locate 91 earthquakes. Two earthquakes were located close to the Baribis Fault line, one of which was felt in Bekasi (southeast of Jakarta) where it registered II-III on the Modified Mercalli Intensity (MMI) scale. The focal mechanism solutions of these events indicate the presence of a thrust fault, which is in good agreement with previous studies, and suggest that the Baribis Fault is active.

scholarly journals Mitigating natural events to avoid disaster in public school buildings: seismic retrofitting of SDN 42 Korong Gadang

2018 ◽  
Vol 229 ◽  
pp. 02021
Author(s):  
James Mwangi ◽  
Laura Putri ◽  
Listhbeth Collins
Keyword(s):  
School Facilities ◽  
Seismic Retrofitting ◽  
Building Structures ◽  
National Agency ◽  
Electrical Grid ◽  
The North ◽  
Australian Plate ◽  
West Sumatra

With over 50 million students, Indonesia has the fourth largest education system in the world. The first twelve years of education are compulsory for all citizens. The students, together with over 3 million teachers spend six (or five in some cases) days a week at over 300,000 schools, typically from 6:30 AM to 2 (or 3) PM. Geographically, Indonesia is traversed by the infamous “ring of fire” and prone to natural events resulting from the tectonic plate movements of the Australian Plate from the South, the Eurasian and Sunda Plates from the North and the Philippine Plate from the East. Left unmitigated, these natural events would lead to natural disasters emanating from resulting earthquakes and leading to tsunamis, landslides, the collapse of building structures and failure of lifelines (roads, pipelines, electrical grid, etc.). In an effort to provide disaster-safe schools, the National Agency for Disaster Management has required that school facilities be a community center in case of disasters and serve as emergency shelters. Retrofit of existing buildings will be needed to comply with government guidelines. This paper presents a case study of the determination of structural deficiencies of an existing school building in SDN 42 Korong Gadang, Padang, West Sumatra and implementation of a seismic retrofit (design and construction) at the same building to mitigate potential earthquake disaster.

Complete Mitochondrial Genome Sequence Analysis and Phylogenetic Location Determination of Hydropsyche Fryeri (Insecta: Trichoptera)

2021 ◽  
Author(s):  
Yimin Li ◽  
Honglin Qin ◽  
Xifa Zhong ◽  
Jingcai Huang ◽  
Yujun Wang ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Genome Sequence ◽  
Complete Mitochondrial Genome ◽  
Phylogenetic Tree Analysis ◽  
Protein Coding ◽  
Mitochondrial Genome Sequence ◽  
Complete Mitochondrial Genome Sequence ◽  
Location Determination ◽  
The Family

Abstract Hydropsyche fryeri belongs to the Trichopteridae family and builds nests in clean and unpolluted streams using stones. It also can be used as an indicator of water quality. Here, we describe the complete mitochondrial genome sequence of Hydropsyche fryeri. The mitochondrial genome is 15,676 bp long and contains 13 protein-coding genes, 22 tRNAs, 2 rRNAs and an AT-rich control region. Phylogenetic tree analysis shows that Hydropsyche fryeri is more closely related to the family Hydroptera than other Trichoptera.

scholarly journals Estimation of the High-Frequency Attenuation Parameter Kappa for the Zagreb (Croatia) Seismic Stations

2020 ◽  
Vol 10 (24) ◽  
pp. 8974
Author(s):  
Davor Stanko ◽  
Snježana Markušić ◽  
Tvrtko Korbar ◽  
Josip Ivančić
Keyword(s):  
High Frequency ◽  
Pannonian Basin ◽  
Epicentral Distance ◽  
Active Faults ◽  
Least Square ◽  
Seismic Zone ◽  
Seismic Stations ◽  
Regional Tectonic ◽  
Surrounding Areas ◽  
The City

The city of Zagreb (Croatian capital) is situated in the contact area of three major regional tectonic units: the SE Alps, NW Dinarides, and Tisza Unit in the southwestern margin of the Pannonian Basin. The Zagreb seismic zone encompasses the Medvednica Mountains and the city of Zagreb with its surrounding areas, which was struck by the strongest instrumentally recorded earthquake (M5.5) on 22 March 2020. The objective of this contribution is the estimation of the high-frequency attenuation spectral parameter kappa (κ) and its local site-specific component for the Zagreb (Croatia) seismic stations to which we were particularly encouraged after the scale of the damage after the Zagreb 2020 earthquake. We tested linear dependence of κ with epicentral distance using traditional linear least square regression, linear regression for data with errors, and constrained model at close distances to estimate near-site attenuation (κ0). Regression-estimated site kappa values at zero-distance are within the range of the uncertainty (±1 standard deviation) with constrained κ0 value as well within the range of existing global κ0 and VS30 (shear wave velocity in the top 30 m) values. Spatial distribution of κ within the Zagreb seismic zone shows that κ is not isotropic and high-frequency attenuation anisotropy is probably affected by local and regional geological variability, regional active faults and a complex tectonic structure in each direction.

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