22 research outputs found
The relocated catalog of the 2021 Flores Sea earthquake
No full textThe relocated catalog of the 2021 Flores Sea earthquakes
Please refer to:
Supendi, P., Rawlinson, N., Prayitno, B.S., Widiyantoro, S., Simanjuntak, A., Palgunadi, K.H., Kurniawan, A., Marliyani, G.I., Nugraha, A.D., Daryono, D., Anugrah, S.D., Fatchurochman, I., Gunawan, M.T., Sadly, M., Adi, S.P., Karnawati, D., Arimuko, A. (2022). The Kalaotoa Fault: A newly identified fault that generated the Mw 7.3 Flores Sea Earthquake. The Seismic Record (2022) 2 (3): 176–185
The relocated catalog of the 2022 Pasaman (West Sumatra) earthquake
No full textThe relocated catalog of the 2022 Pasaman (West Sumatra) earthquake
Please refer to:
Supendi, P., Rawlinson, N., Prayitno, B.S., Sianipar, D., Simanjuntak, A., Widiyantoro, S., Palgunadi, K.H., Kurniawan, A., Shiddiqi, H.A., Nugraha, A.D., Sahara, D.P., Daryono, D., Triyono, R., Adi, S.P., Karnawati, D., Daniarsyad, G., Ahadi, S., Fatchurochman, I., Anugrah, S.D., Heryandoko, N., Sudrajat, A. (2022). A hidden fault revealed by the February 25, 2022 (Mw 6.1) Pasaman Earthquake, West Sumatra, Indonesia, Physics of the Earth and Planetary Interiors, 106973. https://doi.org/10.1016/j.pepi.2022.10697
30-Year Spatial-Temporal Analysis of Air Surface Temperature as Climate Change Mitigation
Get PDFNatural and anthropogenic factors, such as volcanic eruptions and land use, are indirect causes of changes in the micro-scale climate. Over the past 30 years, climate change has been detected with increased air surface temperature (AST) above 30.00C, a phenomenon of Urban Heat Island. Therefore, this study aimed to create a spatial model to see changes in AST in Bandar Lampung City from1990 to 2020. The spatial and temporal analysis uses Landsat data to produce land surface temperature (LST) and AST models. The results showed a temperature rise in the LST area, which tends to be the northern part of Bandar Lampung City, by 25.0oC and above for 30 years. Compare LST and AST from two stations between 30 years is 5.00C. In 1990, the LST concentrated on the spatial distribution of the AST model with a temperature above 30.00C, while in 2020, it diffused to the northern part of Bandar Lampung City. The results concluded that the air temperature in the city has warmed up to 0.46OC (+10C), which is in line with the findings of IPPC and various world cities. It is also in occurrence with the UHI phenomenon since 2014 that climate change is part of mitigation
Analysis of lightning vulnerability level in the City of Mataram and surrounding area using the simple additive weighting method
No full textMataram City, West Lombok and Central Lombok Regencies are areas that have a high level of infrastructure development. This high level of infrastructure development has indirectly increased the risk of lightning strikes in the city of Mataram and its surroundings. This study aims to determine the level of threat, susceptibility, and vulnerability to lightning strikes in the city of Mataram and its surroundings, and to find a correlation between the increase in land use as buildings and settlements with the increase in the number of lightning strikes. The lightning data was obtained from the monitoring results of the Mataram Geophysics Station in the 2017-2021 period which was processed using the Simple Additive Weighting method. From the processing results, the level of vulnerability to lightning in the very high category is in Selaparang and Mataram sub-districts. The results of the Pearson correlation calculation in an increase in the number of areas used as buildings and settlements to an increase in the number of lightning, obtained 14 districts with high Pearson correlation index values and 3 districts with very high Pearson correlation index values which included Batukliang, Sekotong, and Jonggat Districts
Seismic microzonation based on HVSR inversion results for shear wave (Vs30) mapping and soil vulnerability in West Sulawesi and South Sulawesi Regions
No full textThe Horizontal to Vertical Spectral Ratio (HVSR) is a seismic analysis method used to obtain information about subsurface geological characteristics. This method is based on the spectral ratio analysis between the horizontal and vertical components of earthquakes or other vibration sources. HVSR has proven to be an effective tool in evaluating rock layers, layer thickness, rock hardness, and geological hazard potential. In the HVSR method, seismic data are measured using three-component seismometers, the N-S (North-South), E-W (East-West), and vertical components. In this study, the HVSR method is used for Vs30 inversion to estimate shear wave velocity at a depth of 30m. The southern and western regions of Sulawesi have various geological conditions and high seismicity levels. The results of this inversion can be used for mapping soil vulnerability indices. The obtained soil vulnerability index values indicate high vulnerability near the Palu-Koro fault, with A0 9.27 at F0 3.2 Hz. This method can also estimate shear wave velocity values at a depth of 30 m. Vs30 values range from 200 m/s to 500 m/s at various measurement points, indicating variability. According to the SNI 1726:2012 and NEHRP classifications, the research area has soil conditions ranging from medium to soft
IDENTIFIKASI RANGKAIAN GEMPA BUMI PENDAHULUAN (FORESHOCKS) DENGAN PENDEKATAN KORELASI SILANG SINYAL SEISMIK TEMPLATE (STUDI KASUS RANGKAIAN GEMPA BUMI KARO 2017)
No full textPenelitian ini berhasil membuktikan bahwa pendekatan korelasi silang sinyal seismik dapat digunakan untuk mendeteksi kejadian seismik menggunakan waveform dari jaringan BMKG (Badan Meteorologi Klimatologi dan Geofisika). Pendeteksian ini dilakukan untuk melengkapi kejadian gempa bumi yang belum tercatat pada katalog reguler BMKG karena berbagai keterbatasan. Adanya rangkaian kejadian gempa pendahuluan (foreshock sequence) sebelum kejadian gempa Karo M 5,6 tanggal 16 Januari 2017 berhasil teridentifikasi. Tujuan dari penelitian ini adalah melakukan identifikasi kejadian gempa bumi pendahuluan (foreshocks) dengan memanfaatkan data sinyal template gempa bumi M 3,9 yang sebelumnya dianggap sebagai satu-satunya foreshock dalam rangkaian kejadian ini. Penelitian ini berhasil mendeteksi 12 kejadian gempa pendahuluan (foreshocks) setelah diterapkan metode deteksi berbasis korelasi silang. Foreshock mulai terdeteksi pada tanggal 14 Januari 2017 atau dua hari sebelum gempa utama. Magnitudo gempa pendahuluan semakin meningkat secara sistematis sampai kejadian gempa pendahuluan terbesar. Penelitian ini berimplikasi pada manfaat penerapan metode deteksi berbasis waveform untuk mendukung pemahaman fisis sumber gempa dan prediksi gempa bumi di Indonesia.</jats:p
Source process of the 2021 MW6.6 outer rise earthquake off the west coast of northern Sumatra
Get PDFThe complexity of the seismicity pattern for the subduction zone along the oceanic plate triggered the outer rise events and revealed cyclic tectonic deformation conditions along the plate subduction zones. The outer rise earthquakes have been observed along the Sunda arc, following the estimated rupture area of the 2005 MW8.6 Nias earthquakes. Here, we used kinematic waveform inversion (KIWI) to obtain the source parameters of the 14 May 2021 MW6.6 event off the west coast of northern Sumatra and to define the fault plane that triggered this outer rise event. The KIWI algorithm allows two types of seismic source to be configured: the moment tensor model to describe the type of shear with six moment tensor components and the Eikonal model for the rupture of pure double-couple sources. This method was chosen for its flexibility to be applied for different sources of seismicity and also for the automated full-moment tensor solution with real-time monitoring. We used full waveform traces from 8 broadband seismic stations within 1000 km epicentral distances sourced from the Incorporated Research Institutions for Seismology (IRIS-IDA) and Geofon GFZ seismic record databases. The initial origin time and hypocenter values are obtained from the IRIS-IDA. The synthetic seismograms used in the inversion process are based on the existing regional green function database model and were accessed from the KIWI Tools Green's Function Database. The obtained scalar seismic moment value is 1.18×1019 N·m, equivalent to a moment magnitude MW6.6. The source parameters are 140°, 44°, and −99° for the strike, dip, and rake values at a centroid depth of 10.2 km, indicating that this event is a normal fault earthquake that occurred in the outer rise area. The outer rise events with normal faults typically occur at the shallow part of the plate, with nodal-plane dips predominantly in the range of 30°–60° on the weak oceanic lithosphere due to hydrothermal alteration. The stress regime around the plate subduction zone varies both temporally and spatially due to the cyclic influences of megathrust earthquakes. Tensional outer rise earthquakes tend to occur after the megathrust events. The relative timing of these events is not known due to the viscous relaxation of the down going slab and poroelastic response in the trench slope region. The occurrence of the 14 May 2021 earthquake shows the seismicity in the outer rise region in the strongly coupled Sunda arc subduction zone due to elastic bending stress within the duration of the seismic cycle
Design of drought early warning system based on standardized precipitation index prediction using hybrid ARIMA-MLP in Banten province
Get PDFDrought Early Warning System (DEWS) is an effort to disseminate early warning information based on climate and hydrology aspects. The DEWS design uses ARIMA, MLP, and hybrid ARIMA-MLP models to predict drought based on SPI for 1, 3, and 6 months. Predictions were made using ERA5 monthly rainfall data from 1981-2022 corrected based on observation data on 9 grids of observation rain gauges in Banten Province. The design of the ARIMA model is determined by selecting the combination of p and q parameters with the lowest AIC value, while the MLP architecture is determined by referring to the study literature and by trial and error testing. ARIMA models and hybrid models are not able to follow actual data fluctuations and have high error values in both SPI1, SPI3, and SPI6, so they are not recommended in this study. The MLP model has the best prediction ability, namely in SPI6 prediction with NSE value reaching >0.5 and RMSE value
Sosialisasi Peningkatan Literasi Meteorologi Klimatologi Geofisika dan Pemasangan Alat Peringatan Dini Tanah Longsor di Kabupaten Kendal, Jawa Tengah
Get PDFIndonesia merupakan wilayah yang rawan bencana geo-hidrometeorologi. Sinergitas antara Sekolah Tinggi Meteorologi Klimatologi dan Geofisika (STMKG) dan Badan Meteorologi Klimatologi dan Geofisika (BMKG) dengan mitra terkait seperti Badan Penanggulangan Bencana Daerah (BPBD) dan relawan kebencanaan perlu ditingkatkan, karena sering kali inovasi BMKG dalam memberikan pelayanan Meteorologi Klimatologi Geofisika (MKG) tidak serta merta mampu dimanfaatkan secara maksimal oleh masyarakat. Kabupaten Kendal merupakan wilayah yang rawan bencana geo-hidrometeorologi, salah satunya adalah tanah longsor. Oleh karena itu, pengabdian kepada masyarakat ini bertujuan untuk meningkatkan pemahaman masyarakat dan aparatur terkait bencana geo-hidrometeorologi di wilayah Kabupaten Kendal dan sekitarnya, serta mampu mengakses seluruh layanan MKG di salah satu platform mobile InfoBMKG. Selain itu, aparatur terkait juga diharapkan melatih kembali para tokoh masyarakat di wilayah tanggung jawabnya, sehingga terbentuk desa atau masyarakat tangguh bencana di wilayah Kendal dan sekitarnya. Metode yang digunakan dalam PKM ini adalah pendidikan masyarakat dan pelatihan. Adapun evaluasi PKM ini menggunakan pretest dan posttest untuk mengukur keberhasilan dari PKM ini untuk meningkatkan pemahaman peserta PKM. Hasil posttest dan pretest menunjukkan bahwa 90% peserta mengalami peningkatan nilai, bahkan nilainnya lebih besar 80. Data ini mengindikasikan bahwa setelah mengikuti sosialisasi ini, peserta semakin meningkat pengetahuan dan skill terkait bencana geo-hidrometeorologi. Pemasangan alat peringatan dini tanah longsor ini dipasang di Desa Pagertoyo, Kecamatan Limbangan, Kabupaten Kendal diharapkan menjadi alat peringatan dini tanah longsor di wilayah Kabupaten Kendal, sehingga dapat meminimalisir korban jiwa jika terjadi tanah longsor di wilayah tersebut
The Mount Anak Krakatau landslide scenario for tsunami modeling in Banten
No full textThe eruption of Mount Anak Krakatau occurred on December 22, 2018, in the Sunda Straits, Indonesia, causing a tsunami that affected the coastal area of Banten Province. We use COMCOT 1.7 to make a tsunami model based on flank collapse caused by a landslide tsunami. The aim of study is to remodel past events to anticipate the mechanism and impact of the damage in the future. Bathymetry and topography are integrated to become high resolution data with a grid area of 49.8 meterss. The flank collapse scenario is applied with slide dimensions of 2000 meters long, 1500 meters wide, and 228 meters thick following previous study. The tsunami model consists of the initial tide model and the coastal model. The highest tsunami run-up of the tide model is in Carita of 1.9 meters height. The fastest arrival time of the tide model is in Sumur of 19 minutes. which is slightly different from previous studies due to different modeling applications and different initial tide locations. The highest tsunami run-up of the coastal model is in Lesung and Sumur of 2.5 meters height which almost matches the results of field observations
