This research is concerned with an analysis of the level of vulnerability for an earthquake disaster in Lembang district,an area in West Java that includes the Bandung basin and has a high potential for earthquake dis...This research is concerned with an analysis of the level of vulnerability for an earthquake disaster in Lembang district,an area in West Java that includes the Bandung basin and has a high potential for earthquake disaster.The Lembang district is close to the active Lembang fault whose movement can cause earthquakes of magnitude 7 on the Richter scale(Tempo Interaktif,May 11,2010).The research method used to assess the level of vulnerability is essentially a descriptive approach.The data analysis is based on calculating an earthquake disaster risk index(EDRI),which is in turn based on assessment of the region's social,physical and economic vulnerabilities.The vulnerability level for earthquake disaster in the Lembang is ranked as medium category.The social vulnerability of the population is the major contributing factor given the high population density and growth rate for the region.The physical characteristics of the district,which includes mild temperatures and attractive scenery,make many people want to stay in and visit Lembang.The construction quality of buildings is so bad that they are not designed to withstand earthquakes,so improvement of building infrastructure is an alternative to reducing the various physical vulnerabilities.展开更多
The Indonesian region is one of the most seismically active zones on the earth. On December 26, 2004, an M_S 8.7 earthquake (as measured by the China Seismograph Network, or M_w = 9.3 as measured by USGS) struck the w...The Indonesian region is one of the most seismically active zones on the earth. On December 26, 2004, an M_S 8.7 earthquake (as measured by the China Seismograph Network, or M_w = 9.3 as measured by USGS) struck the west coast of northern Sumatra, Indonesia. By its magnitude it is classified as the world’s fourth largest earthquake since 1900 and the largest one since the 1964 Alaska earthquake. The spatial distribution of the relocation of larger aftershocks (M>4.5) following the main shock suggests a length and width of the rupture of about 1200km and 200km, respectively. The shock triggered massive tsunamis that affected several countries throughout South and Southeast Asia. It is a shallow interplate event of thrust type in the trench. Its epicenter is located at the northwestern end of the Indonesia-Melanesia plate boundary tectonic zone. In 2004, eight shocks of M≥7.0 occurred in this area, showing a migration from east to west. It implies that these shocks represent a correlated and consistent dynamic process along this subduction zone. These interplate events are associated with convergence of several plates and their fast motion in this region, which result in strong and complex structures and deformation. The India-Australia plate is underthrusting toward the Sunda continental block or Burma plate at a low angle, producing a great locked area on the shallow portion of the subduction zone where enormous strain is accumulated. Interseismic uplift recorded by coral growth and horizontal velocities measured by GPS show the geometry of the locked portion of the Sumatra subduction zone. The vertical and horizontal data reasonably match with a model in which the plate interface is fully locked over a significant width. This locked fault zone extends to a horizontal distance of 132km from the trench, which corresponds to a depth of 50km. The sudden ruptures and large-scale slip of this locked area as a release of stress occurred, are the direct cause of the M8.7 earthquake near Indonesia in 2004.展开更多
The seismic frequency increased significantly in the Yunnan region after the Indonesia earthquake with M_S8.7 on December 26, 2004. This was estimated by analyzing the seismic frequency ratio between the influenced an...The seismic frequency increased significantly in the Yunnan region after the Indonesia earthquake with M_S8.7 on December 26, 2004. This was estimated by analyzing the seismic frequency ratio between the influenced and normal times, the spatial distribution characteristics of the increased seismic frequency, the temporal-spatial distribution and types of seismic swarms. Seismic frequency increased at 71.3% of the statistical sites in the Yunnan area. The maximal increase ratio is 18.2.展开更多
文摘This research is concerned with an analysis of the level of vulnerability for an earthquake disaster in Lembang district,an area in West Java that includes the Bandung basin and has a high potential for earthquake disaster.The Lembang district is close to the active Lembang fault whose movement can cause earthquakes of magnitude 7 on the Richter scale(Tempo Interaktif,May 11,2010).The research method used to assess the level of vulnerability is essentially a descriptive approach.The data analysis is based on calculating an earthquake disaster risk index(EDRI),which is in turn based on assessment of the region's social,physical and economic vulnerabilities.The vulnerability level for earthquake disaster in the Lembang is ranked as medium category.The social vulnerability of the population is the major contributing factor given the high population density and growth rate for the region.The physical characteristics of the district,which includes mild temperatures and attractive scenery,make many people want to stay in and visit Lembang.The construction quality of buildings is so bad that they are not designed to withstand earthquakes,so improvement of building infrastructure is an alternative to reducing the various physical vulnerabilities.
文摘The Indonesian region is one of the most seismically active zones on the earth. On December 26, 2004, an M_S 8.7 earthquake (as measured by the China Seismograph Network, or M_w = 9.3 as measured by USGS) struck the west coast of northern Sumatra, Indonesia. By its magnitude it is classified as the world’s fourth largest earthquake since 1900 and the largest one since the 1964 Alaska earthquake. The spatial distribution of the relocation of larger aftershocks (M>4.5) following the main shock suggests a length and width of the rupture of about 1200km and 200km, respectively. The shock triggered massive tsunamis that affected several countries throughout South and Southeast Asia. It is a shallow interplate event of thrust type in the trench. Its epicenter is located at the northwestern end of the Indonesia-Melanesia plate boundary tectonic zone. In 2004, eight shocks of M≥7.0 occurred in this area, showing a migration from east to west. It implies that these shocks represent a correlated and consistent dynamic process along this subduction zone. These interplate events are associated with convergence of several plates and their fast motion in this region, which result in strong and complex structures and deformation. The India-Australia plate is underthrusting toward the Sunda continental block or Burma plate at a low angle, producing a great locked area on the shallow portion of the subduction zone where enormous strain is accumulated. Interseismic uplift recorded by coral growth and horizontal velocities measured by GPS show the geometry of the locked portion of the Sumatra subduction zone. The vertical and horizontal data reasonably match with a model in which the plate interface is fully locked over a significant width. This locked fault zone extends to a horizontal distance of 132km from the trench, which corresponds to a depth of 50km. The sudden ruptures and large-scale slip of this locked area as a release of stress occurred, are the direct cause of the M8.7 earthquake near Indonesia in 2004.
文摘The seismic frequency increased significantly in the Yunnan region after the Indonesia earthquake with M_S8.7 on December 26, 2004. This was estimated by analyzing the seismic frequency ratio between the influenced and normal times, the spatial distribution characteristics of the increased seismic frequency, the temporal-spatial distribution and types of seismic swarms. Seismic frequency increased at 71.3% of the statistical sites in the Yunnan area. The maximal increase ratio is 18.2.
