Seismic Tomographic Imaging: Algorithm and Files

List of input and output files

1. PICKS-BISC-1964-2017: Arrival time data the bulletin of International Seismological Center (ISC) for earthquakes that have occurred around the Sumatran Fault System spanning latitudes 10º N - 10º S and longitudes 93º E-114º E.
2. SFILE-06-18: Hand-picked data using SEISAN software. Waveform is obtained from Incorporated Research Institutions for Seismology (IRIS)
3. Global list of seismic stations and their locations (courtesy ISC)
4. A_VMD2: The algorithm used to generated the final model
5. A11-MODEL-DEP-SLICE: Output file for representative depths
6. A11-MODEL-LAT-SLICE: Output file for North-South vertical cross-sections
7. A11-MODEL-LON-SLICE: Output file for East-West vertical cross-sections
8. A11_MODEL-3D: Output file for 3-D model of the study region
9. A_VMD.INC: A common file required by many subroutines in the main algorithm
10. EVENTS: All earthquakes used in the study
11. A13-RESIDUALS: Computed traveltime residuals for all stations and for all events.
12. List of 1-D velocity models. (the iasp91 model is used)

Tomographic results show low-velocity (low-V) anomalies that reflect both accretion and possibly, asthenospheric upwelling associated with subduction of the Australian plate beneath the Eurasian plate around the Sumatra subduction zone (SSZ). The prominent low-V anomaly is thickest around the Conrad, extending beneath Malacca Strait and parts of Peninsular Malaysia, but disappears around the Moho (which appears to be less than 35 km) in the region. Below the Moho, the subducting Australian slab, represented by a high-velocity (high-V) anomaly, trends in the orientation of Sumatra. At these depths, the eastern shorelines of Sumatra, most parts of Malacca Strait and the west coast of Peninsular Malaysia show varying degrees of positive velocity anomalies. We consider that asthenospheric upwelling around the SSZ provide heat source for the 40 or more hot springs distributed North-South in Peninsular Malaysia. Different East-West and North-South cross-sections reveal the subsurface anomalies at various parts of the region. The predominant low-V anomaly is less than 35 km in depth but other low-V anomalies are deeper.

数据集清单

1. PICKS-BISC-1964-2017：国际地震中心（ISC）发布的环绕苏门答腊断层系统发生的地震到达时间数据，该系统横跨北纬10°至南纬10°，东经93°至东经114°。
2. SFILE-06-18：使用SEISAN软件手工挑选的数据。波形数据来源于综合地震学研究所（IRIS）。
3. 全球地震台站及其位置清单（由ISC提供）。
4. A_VMD2：生成最终模型的算法。
5. A11-MODEL-DEP-SLICE：代表深度输出文件。
6. A11-MODEL-LAT-SLICE：南北垂直横截面输出文件。
7. A11-MODEL-LON-SLICE：东西垂直横截面输出文件。
8. A11_MODEL-3D：研究区域三维模型输出文件。
9. A_VMD.INC：主算法中许多子例程所需共用文件。
10. EVENTS：研究中使用到的所有地震事件。
11. A13-RESIDUALS：对所有台站和所有事件计算出的旅行时间残差。
12. 一维速度模型清单。（使用iasp91模型）

层析成像结果显示，低速度（低-V）异常现象反映了与澳大利亚板块在欧亚板块下俯冲相关的沉积和可能的地幔上涌，该现象在苏门答腊俯冲带（SSZ）周围尤为显著。显著的低-V异常最厚处位于康拉德附近，延伸至马六甲海峡和马来西亚半岛的部分地区，但在莫霍面（此处似乎小于35公里）附近消失。莫霍面以下，代表澳大利亚板块下方的下沉地壳，以高速度（高-V）异常形式存在，其走向与苏门答腊一致。在这些深度，苏门答腊的东海岸线、马六甲海峡的大部分地区以及马来西亚半岛的西海岸显示出不同程度的正速度异常。我们认为，SSZ周围的地幔上涌为马来西亚半岛南北分布的40多个温泉提供了热源。不同的东西向和南北向横截面揭示了该区域不同部分的地下异常。主要的低-V异常深度小于35公里，但其他低-V异常则更深。