scholarly journals The Spatio-temporal Tectonic Condition and Microzonation Map of Malang Region after the 2021 M6.1 Malang Earthquake for Disaster Risk Mitigation

2021 ◽  
Vol 933 (1) ◽  
pp. 012031
Author(s):  
Y Muntafi ◽  
N Nojima
Keyword(s):  
Risk Mitigation ◽  
Hazard Analysis ◽  
High Stress ◽  
B Value ◽  
Disaster Mitigation ◽  
Likelihood Method ◽  
Spectral Acceleration ◽  
Value Analysis ◽  
The Future ◽  
Spatio Temporal

Abstract The M6.1 earthquake which hit Malang and its surroundings in 2021 resulted in fatalities and over 10,400 damaged houses. Several seismicity studies have been carried out for Malang region, but no specific studies have implied the M6.1 Malang earthquake yet. This study addresses such gap by investigating the Spatio-temporal b-value of Gutenberg-Richter Law and generating the microzonation maps of spectral acceleration by considering the effects of the M6.1 Malang earthquake. The earthquake data compiled from the national and international earthquake catalogs were homogenized into a moment magnitude scale. The b-value analysis was calculated using the Maximum Likelihood method and spatio-temporal mapping. Several ground motion prediction equations (GMPEs) were selected for subduction and shallow crustal earthquake sources to generate probabilistic seismic hazard analysis (PSHA). PSHA was conducted using the 2% probability of exceedance in 50 years. The results show that the b-value after the M6.1 Malang earthquake still tends to decrease, indicating a relatively-high stress level which accommodates the potential for large earthquakes in the future. The microzonation maps for Malang region show that the southern part of Malang has a higher spectral acceleration value than the others. Therefore, these findings can be considered in the future disaster mitigation plan.

scholarly journals THE ANALYSIS OF SEISMOTECTONICS, PERIODICITY, AND CHANGING OF QUAKES LEVEL IN WEST NUSA TENGGARA AREA BASED ON 1973 – 2015 DATA

2019 ◽  
Vol 2 (1) ◽  
pp. 37
Author(s):  
Melinda Utami Istiqomah ◽  
Bambang Sunardi ◽  
Marzuki Marzuki ◽  
Suhayat Minardi
Keyword(s):  
High Stress ◽  
The United States ◽  
B Value ◽  
Disaster Mitigation ◽  
Likelihood Method ◽  
United States Geological Survey ◽  
Seismicity Rate ◽  
A Value ◽  
Value Range ◽  
Seismicity Rate Changes

This research was conducted as one of the earthquake disaster mitigation efforts in Nusa Tenggara Barat region, because this region is one of the regions in Indonesia which has a relatively high level of seismicity. The purpose of this research is to determine seismotectonic parameter, earthquake periodicity along with the average of seismicity rate changes in Nusa Tenggara Barat region. The data used in this research is the data sourced from the United States Geological Survey (USGS) and Badan Meteorologi Klimatologi dan Geofisika (BMKG) from Januari 1973 until February 2015 for Bali Strait region up to Banda Sea with coordinate boundaries of 1140–1300 East Longitude and 40-130 South Latitude. This research was conducted using the maximum likelihood method with second party of software Zmap ver 6.0 also software ArcGis ver 10 to map seismotectonic parameter, periodicity and the average velocity of seismicity rate changes. Variation b value range between 0.972–1.44, a low value of b are associated with high stress levels, and vice versa. The a value range between 6.67- 9.1, its show that the regions with high a value experience a relatively high earthquake incidence rate, and vice versa. The density of earthquake is about -2.63 to -2.01 logN/km2 or the occurrence of earthquakes in the area is very rare. Earthquake periodicity with magnitude (M) 6 SR is 5 to 18 year, M 6.5 SR is 16 to 67 year, M 7 SR is 54 to 304 year, and M 7.5 SR is 178 to 1.386 year. The average of seismicity rate changes on a case that occurred in Sumbawa in 1982 is more than 125%, meanwhile the earthquake that occurred in 2009 is more than 75%.Copyright © 2019IPR. All rights reserved.

Judge the Possible Areas in Eastern Part of Inner Mongolia where Strong Earthquakes Occur in the Future by Utilizing b-Value

2012 ◽  
Vol 518-523 ◽  
pp. 5616-5622
Author(s):  
Xiao Ming Han ◽  
Ding Xue ◽  
Bo Hu
Keyword(s):  
Inner Mongolia ◽  
Strong Earthquake ◽  
Least Square Method ◽  
B Value ◽  
Geological Structure ◽  
Least Square ◽  
Space Distribution ◽  
Likelihood Method ◽  
Time Scanning ◽  
The Future

The Zhalantun district of eastern part of Inner Mongolia is located at the northern section of Greater Khingan seismic belt, and it has complicated geological structure, with relatively dynamic moderately strong earthquake in past times and modern times. The seismic activities in this district is selected as the research object; based on the integrity analysis toward seismic sequence in the district, least square method is used to conduct time scanning calculation of b-value, and maximum likelihood method is used to conduct space scanning calculation of b-value. The b-value during the time scanning is the mean b-value of research zone in every scanning window, so its amplitude of variation is not quite great, with range of variation of b-value basically staying within 0.78-1.13, and range of error staying within 0.04-0.065. The space scanning results indicate that the space distribution range of b-value of Zhalantun district basically stays within 0.4-1.6, and the range of error is 0.045-0.085. The low b-value zone is the north central section of Alun River breakage, with b-value basically distributed within 0.5-0.7, which indicates that the earth crust medium of this zone is under the state of high horizontal stress accumulation and it is the dangerous zone where moderately strong earthquake or more occurs in the future.

scholarly journals Changes in the b value in and around the focal areas of the M6.9 and M6.8 earthquakes off the coast of Miyagi prefecture, Japan, in 2021

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
K. Z. Nanjo ◽  
A. Yoshida
Keyword(s):  
Source Region ◽  
High Stress ◽  
Tohoku Earthquake ◽  
B Value ◽  
2011 Tohoku Earthquake ◽  
East Side ◽  
Coseismic Slip ◽  
The 2011 Tohoku Earthquake ◽  
Value Analysis ◽  
Miyagi Prefecture

AbstractWe investigated changes in the b value of the Gutenberg–Richter’s law in and around the focal areas of earthquakes on March 20 and on May 1, 2021, with magnitude (M) 6.9 and 6.8, respectively, which occurred off the Pacific coast of Miyagi prefecture, northeastern Japan. We showed that the b value in these focal areas had been noticeably small, especially within a few years before the occurrence of the M6.9 earthquake in its vicinity, indicating that differential stress had been high in the focal areas. The coseismic slip of the 2011 Tohoku earthquake seems to have stopped just short of the east side of the focus of the M6.9 earthquake. Furthermore, the afterslip of the 2011 Tohoku earthquake was relatively small in the focal areas of the M6.9 and M6.8 earthquakes, compared to the surrounding regions. In addition, the focus of the M6.9 earthquake was situated close to the border point where the interplate slip in the period from 2012 through 2021 has been considerably larger on the northern side than on the southern side. The high-stress state inferred by the b-value analysis is concordant with those characteristics of interplate slip events. We found that the M6.8 earthquake on May 1 occurred near an area where the b value remained small, even after the M6.9 quake. The ruptured areas by the two earthquakes now seem to almost coincide with the small-b-value region that had existed before their occurrence. The b value on the east side of the focal areas of the M6.9 and M6.8 earthquakes which corresponds to the eastern part of the source region of the 1978 off-Miyagi prefecture earthquake was consistently large, while the seismicity enhanced by the two earthquakes also shows a large b value, implying that stress in the region has not been very high.

scholarly journals Pemetaan Spectral Accelaration Daerah Yogyakarta Dengan Pendekatan Probabilistic Seismic Hazard Analysis

2020 ◽  
Vol 16 (3) ◽  
pp. 217
Author(s):  
Eka Faisal Nurhidayatullah ◽  
Dwi Kurniati
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
B Value ◽  
Probabilistic Seismic Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Probabilistic Seismic Hazard ◽  
Spectral Acceleration ◽  
A Value

Daerah Istimewa Yogyakarta (DIY) memiliki tingkat aktivitas seismik yang tinggi, sudah berulang kali mengalami kejadian bencana gempa yang merugikan. Berbagai upaya untuk meminimalisir dampak bencana gempa bumi sudah dilakukan sebelumnya. Salah satunya yaitu dengan menerbitkan dan memperbaharui peta gempa secara berkala. Indonesia sedari lama menggunakan gempa sebagai acuan perencanaan infrastruktur, yaitu sejak tahun 1983 hingga yang terbaru yaitu peta gempa tahun 2017. Namun gempa berkekuatan 6,3 SR yang terjadi pada bulan Mei 2006 menunjukkan masih banyak bangunan terutama engineered yang hancur. Melihat begitu dahsyatnya dampak yang ditimbulkan oleh gempa tersebut maka mitigasi lebih lanjut terkait dengan bencana gempa perlu dilakukan untuk meminimalisir kerugian apabila bencana sejenis kembali terjadi dikemudian hari. Perlu dilakukan pembuatan peta gempa berskala mikro (daerah) guna perencanaan, estimasi kerusakan bangunan, korban jiwa dan kerugian secara ekonomi akibat kejadian gempa dimasa datang mengingat peta gempa yang dirilis pemerintah sampai saat ini masih berskala makro (nasional). Tujuan penelitian ini yaitu menganalisis angka percepatan tanah permukaan dengan luaran berupa peta gempa berskala mikro pada wilayah provinsi Yogyakarta. Data gempa diperoleh dari rekaman gempa dengan maksimum radius 500 km dari pusat kota Yogyakarta yang telah dipublikasi oleh USGS antara tahun 1900 sampai dengan 2020. Declustering dilakukan terhadap data historis dan sebaran peta gempa sehingga hanya digunakan gempa utama dengan magnitude ≥ 5 Mw. Dalam studi ini digunakan fungsi atenuasi Campel-Bozorgonia NGA (2008) untuk gempa Sesar, Atkinson-Boore Worldwide Data NGA (2003) intraslab dan interface untuk gempa subduksi benioff serta megahtrust. Nilai spectral acceleration (Sa) diperoleh dengan  menggunakan pendekatan Probabilistic Seismic Hazard Analysis (PSHA). Hasil analisis probabilistik percepatan gerakan tanah kemudian dikembangkan menjadi peta pada beberapa periode ulang gempa. Berdasarkan hasil penelitian diperoleh peta probabilitas terlampaui 7% dalam 75 tahun didapatkan nilai spectral acceleration percepatan tanah puncak (PGA) berada dikisaran 0,525 – 0,688g, periode pendek 1,055 – 1,7g serta periode 1 detik 0,535 -0,695g. Pada peta probabilitas terlampaui 2% dalam 50 tahun diperoleh nilai spectral acceleration PGA yaitu 0,6 – 0,79g, periode pendek 1,325 – 2,1 g serta periode panjang 0,65 -0,85 g. Sedangkan pada peta probabilitas terlampaui 2% dalam 100 tahun, nilai spectral acceleration PGA berada diantara 0,66 – 0,86g, periode pendek  1,625 – 2,465g serta periode 1 detik 0,755 -0,995g. Tingkat aktivitas kegempaan pada klaster subduksi megathrust 1 serta sesar opak dilihat dari a-value, b-value  serta Mc ditengarai memicu adanya peningkatan nilai spectral acceleration wilayah Yogyakarta dibanding peta hazard tahun 2017.

scholarly journals InSAR Monitoring of Landslide Activity in Dominica

2021 ◽  
Vol 13 (4) ◽  
pp. 815
Author(s):  
Mary-Anne Fobert ◽  
Vern Singhroy ◽  
John G. Spray
Keyword(s):  
Risk Mitigation ◽  
Disaster Mitigation ◽  
Aerial Images ◽  
Landslide Inventory ◽  
Landslide Risk ◽  
Susceptibility Map ◽  
Interferometric Synthetic Aperture Radar ◽  
Rainfall Events ◽  
Susceptibility Maps ◽  
Digital Elevation

Dominica is a geologically young, volcanic island in the eastern Caribbean. Due to its rugged terrain, substantial rainfall, and distinct soil characteristics, it is highly vulnerable to landslides. The dominant triggers of these landslides are hurricanes, tropical storms, and heavy prolonged rainfall events. These events frequently lead to loss of life and the need for a growing portion of the island’s annual budget to cover the considerable cost of reconstruction and recovery. For disaster risk mitigation and landslide risk assessment, landslide inventory and susceptibility maps are essential. Landslide inventory maps record existing landslides and include details on their type, location, spatial extent, and time of occurrence. These data are integrated (when possible) with the landslide trigger and pre-failure slope conditions to generate or validate a susceptibility map. The susceptibility map is used to identify the level of potential landslide risk (low, moderate, or high). In Dominica, these maps are produced using optical satellite and aerial images, digital elevation models, and historic landslide inventory data. This study illustrates the benefits of using satellite Interferometric Synthetic Aperture Radar (InSAR) to refine these maps. Our study shows that when using continuous high-resolution InSAR data, active slopes can be identified and monitored. This information can be used to highlight areas most at risk (for use in validating and updating the susceptibility map), and can constrain the time of occurrence of when the landslide was initiated (for use in landslide inventory mapping). Our study shows that InSAR can be used to assist in the investigation of pre-failure slope conditions. For instance, our initial findings suggest there is more land motion prior to failure on clay soils with gentler slopes than on those with steeper slopes. A greater understanding of pre-failure slope conditions will support the generation of a more dependable susceptibility map. Our study also discusses the integration of InSAR deformation-rate maps and time-series analysis with rainfall data in support of the development of rainfall thresholds for different terrains. The information provided by InSAR can enhance inventory and susceptibility mapping, which will better assist with the island’s current disaster mitigation and resiliency efforts.

Related spatio-temporal changes in hypocenters and the b value in the 2017 Kagoshima Bay swarm activity indicating a rise of hot fluids

2018 ◽  
Vol 749 ◽  
pp. 35-45
Author(s):  
K.Z. Nanjo ◽  
K. Miyaoka ◽  
K. Tamaribuchi ◽  
A. Kobayashi ◽  
A. Yoshida
Keyword(s):  
B Value ◽  
Temporal Changes ◽  
Kagoshima Bay ◽  
Spatio Temporal ◽  
Swarm Activity

scholarly journals Spatio-temporal analysis of Plasmodium falciparum prevalence to understand the past and chart the future of malaria control in Kenya

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Peter M. Macharia ◽  
Emanuele Giorgi ◽  
Abdisalan M. Noor ◽  
Ejersa Waqo ◽  
Rebecca Kiptui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Malaria Control ◽  
Temporal Analysis ◽  
The Past ◽  
The Future ◽  
Spatio Temporal

scholarly journals Seismic analysis using maximum likelihood of gutenberg-richter

2017 ◽  
Vol 1 (1) ◽  
pp. 34-40
Author(s):  
Arum Handini Primandari ◽  
Khusnul Khotimah
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Method ◽  
Seismic Analysis ◽  
B Value ◽  
Likelihood Method ◽  
Natural Phenomena ◽  
Earthquake Occurrence ◽  
Precise Prediction ◽  
Great Damage

An earthquake is one of catastrophe which often claim numerous lives and cause great damage to infrastructure. Multiple studies from various field have been conducted in order to make a precise prediction of earthquake occurrence, such as recognizing the natural phenomena symptoms leading to the shaking and ground rupture. However, up till now there is no definite method that can predict the time and place in which earthquake will occur. By assuming that the number of earthquake follow Gutenberg-Richter law, we work b-value derived using Maximum Likelihood Method to calculate the probability of earthquake happen in the next few years. The southern sea of D.I. Yogyakarta was divided into four areas to simplify the analysis. As the result, in the next five years the first and second area have high enough probability (>0.3) to undergo more than 6.0-magnitude earthquake.

Seismicity associated with 2018 and 2020 hydraulic stimulations at EGS in Helsinki, Finland, shows limited earthquake interaction: Implication for seismic hazard assessment

2021 ◽  
Author(s):  
Grzegorz Kwiatek ◽  
Maria Leonhardt ◽  
Patricia Martínez-Garzón ◽  
Matti Pentti ◽  
Marco Bohnhoff ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Energy Input ◽  
Stress Transfer ◽  
Seismic Hazard Assessment ◽  
B Value ◽  
Temporal Distance ◽  
Probabilistic Seismic Hazard Assessment ◽  
Interevent Time ◽  
Spatio Temporal

<p>In this study we investigate the statistical spatio-temporal characteristics induced seismicity associated with two stimulation campaigns performed in 2018 and 2020 in a 6.1 km deep geothermal well near Helsinki, Finland as part of the St1 Deep Heat project. We aim to find out whether the seismic activity is passively responding to injection operations, or whether we observe signatures of significant stress transfer and strong interactions between events. The former suggests stable relaxation of seismic energy proportional to hydraulic energy input, while the latter includes stress transfer as an additional source of stress perturbation, hence implying larger seismic hazard.</p><p>The selected catalogs from 2018 and 2020 stimulation contained in total 60,814 and 4,368 seismic events, respectively, recorded during and after stimulation campaigns and above the local magnitude of M -1.5. The analyzed parameters include magnitude-frequency b-value, correlation integral (c-value), fractal dimension (D-value), interevent time statistics, magnitude correlation, interevent time ratio and generalized spatio-temporal distance between earthquakes. The initial observations suggest significant time-invariance of the magnitude-frequency b-value, and increased D and c-values only at high injection rates, the latter also guiding the rate of seismicity. The seismicity covering the stimulation period neither provide signatures of magnitude correlations, nor temporal clustering or anticlustering. The interevent time statistics are generally characterized with Gamma distribution (close to Poissonian distribution), and the generalized spatio-temporal distance suggest very limited triggering (90% of the catalog was classified as background seismicity). The observable parameters suggest the seismicity passively respond to hydraulic energy input rate with little to no time delay, and the total seismic moment is proportional to total hydraulic energy input. The performed study provides the base for implementation of time-dependent probabilistic seismic hazard assessment for the site.</p>

Godard’s suburban years

2018 ◽  
Author(s):  
Térésa Faucon
Keyword(s):  
Science Fiction ◽  
Surprising Effect ◽  
The Future ◽  
Spatio Temporal ◽  
The 1960S ◽  
Late Modern ◽  
Rupture Characteristic

Far from a simple backdrop, the lived environment was for Jean-Luc Godard capable of eliciting specific modes of cinematographic thought; choice of locations could impact the shape and feel of a film more than its screenplay. Prevalent in his works of the 1960s are suburban landscapes and locales, from the villas, cafés and roadways frequented by the characters of Bande à part (1964) to the high-rises of La Courneuve shown in the essay in phenomenology 2 ou 3 choses que je sais d’elle (1967). Without positing an equivalence between suburban heterogeneity and Godard’s jarring late-modern aesthetic, the author argues for the generative, transgressive capacity of a capitalist space in the throes of transformation and shot through with fragments of history. Shooting near Joinville-le-Pont and Vincennes in Bande à part, Godard pays homage to those pioneers who came before him, like Mack Sennett or Louis Feuillade. In other contexts, like the science-fiction sendup Alphaville (1965), he finds signs of the future in the present, showing Lemmy Caution moving through sleek, well-lit neighbourhoods of high-rises. The spatio-temporal rupture characteristic of Godard’s approach to suburban space resurfaces to surprising effect in Holy Motors (Leos Carax, 2012).

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