Abstract. Near the northern border of Sumatra, the right-lateral
strike–slip Sumatran fault zone splits into two branches and extends into
the offshore, as revealed by seismic sounding surveys. However, due to its
strike–slip faulting characteristics, the Sumatran fault zone's activity is
rarely believed to cause tsunami hazards in this region. According to two
reprocessed reflection seismic profiles, the extended Sumatran fault zone is
strongly associated with chaotic facies, indicating that large submarine
landslides have been triggered. Coastal steep slopes and new subsurface
characteristics of submarine landslide deposits were mapped using recently
acquired high-resolution shallow bathymetry data. Slope stability analysis
revealed some targets with steep morphology to be close to failure. In an
extreme hypothetical case, an earthquake of Mw 7 or more occurred, and
the strong ground shaking triggered a submarine landslide off the northern
shore of Sumatra. Based on a simulation of tsunami wave propagation in
shallow water, the results of this study indicate that a potential tsunami hazard
from several submarine landslide sources triggered by the strike–slip fault
system can generate a tsunami as high as 4–8 m at several locations along
the northern coast of Aceh. The landslide tsunami hazard assessment and
early warning systems in this study area can be improved on the basis of
this proposed scenario.