#TITLE_ALTERNATIVE#

• Main Author: YUDHIARTI (NIM : 22411008) ; Pembimbing : Afnimar, Ph.D, NAFISAH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/19037
• Institution: Institut Teknologi Bandung

The complexity of tectonics in Sunda Strait has been influenced by the transition zone of oblique subduction in western Sumatera and normal subduction in southern Java. In addition, the influence of the graben, Sumatra fault and volcanic activity increases the intensity of seismicity in the region. The presence of seismic gap in Sunda Strait region potentially causes megathrust earthquake. Focal mechanism from IRIS can describe the fault plane and the stress orientation that worked in Sunda Strait. The major earthquake in Sunda Strait is dominated by the deep earthquake (>50 km) with thrust faulting mechanism at subduction zone which has the stress orientation of southwest-northeast and strike ±291&#8304;. Focal mechanisms of earthquake that occured in the graben structure is normal faulting result of gravity collapse. Graben occurred by extension of the Mentawai block and Sumatera block continues to move towards northwest. An earthquake with dextral strike-slip faulting mechanism occurred on Sumatran fault. This earthquake occured at the shallow depths (< 50 km) with the stress orientation from the south, the direction strike of northwest to southeast. Subduction slab transition beneath the Sunda Strait showed the presence of a tear fault in Sunda Strait. It generated the magmatic gap to form the volcanic arc with the volcanic lineament pattern of southwest-northeast corresponding with the subduction slab orientation beneath the Sunda Strait.