preview

High Seismicity Of West Sumatera

Decent Essays

Figure 3 shows the high seismicity of West Sumatera. On the map shows that the density of seismicity of West Sumatera is more visible around the island of Nias (Zone 5), south of Siberut Island, around the Mentawai Islands (Zone 7), along the active fault zone of Sumatra and also in the subduction path. This high seismic density is thought to be influenced by tectonic activity owned by West Sumatra. These tectonic activities include subduction zones located in the western part of Sumatra Island stretching along its coastline, underwater active fault activities such as the Mentawai fault, and the activity of the Sumatran Fault. Most of the earthquakes caused by the subduction zone and the active fault zone of Sumatra are potentially large …show more content…

These three areas are seismic zones (regime stress) are quite dynamic and has the potential to cause significant and destructive earthquake. A region with a low-b value is an active seismic area that is still locked called a locked zone. Locked zone can someday bring significant and destructive earthquakes. Thus, areas with low-b values as mentioned above need to be aware of significant earthquakes. While areas with a high b-value as seen in the north of Nias Island are referred to as creeping zones, are active fault zones that do not experience energy accumulation and do not experience slippage. This is in accordance with previous research that low b-values are associated with rock stress conditions in the area high, and vice versa. [7]

The results of this observation are compared with observations in the period 1980-2016 (Syafriani, 2017: International Conference-Bali) shown in Figure 5 (a), it is found that the b-value in the period (1971-2017) is higher than the b-value in the period (1980-2016). The b-value in the period (1971-2017) is 0.956, while the b-value in the period (1980-2016) is 0.928. This is also indicated by the blue color in the southern island of Siberut (period 1980-2016) more concentrated than the blue color in the southern island of Siberut (period 1971-2017). The difference in this condition is suspected because the area around Siberut Island after 2016 has been

Get Access