Understanding how seamount affects subduction earthquakes is
Understanding how seamount affects subduction earthquakes is important for assessing seismic andtsunami hazard, however it is still subject of debate. There are two contrast group of scientist thathave different insight to address the effect of seamounts. One group suggest that seamount is ubiq-uitous feature of seafloor that have profound effect of large earthquakes (Scholz and Small, 1997);(Trhu et al., 2012). In the contrary, seamount is a barrier to inhibit coseismic rupture propagation(Kodaira et al.
, 2000); (Mochizuki et al., 2008); (Wang and Bilek, 2011); (Singh et al., 2011);(Yang et al.
, 2013).There is a contention that subducting seamount generates large earthquake. Because it subductswith numerous amount of frictional force and become an ideal asperity (Scholz and Small, 1997).On the other hand, Yang et al. (2013) proposed that subducting seamounts causes an erosion onthe overriding plate and carried sediment material into seismogenic zone. The existence of destinedfluid-rich sediment in the vicinity of of subducting seamounts lead to reduce the normal and fric-tional force simultaneously, leading to elastic strain accumulation and therefore causing aseismicbehavior (Singh et al., 2011); (Mochizuki et al., 2008).
Possibly, statements that arguing the existences of subducting seamount aseismically is still ac-ceptable if we put globally. It has been long study suggested that subducting seamount or roughrelief of seafloor is tend to behave aseismically (Wang and Bilek, 2011). Moreover, review studyby Wang and Bilek (2014) stated that rough relief of seafloor like subducting seamount causesthe fault to creep at rates nearly similar to the subduction rate (using geodetic instrumentation).However, observation of bathymetry, magnetic anomaly, and seismic reflection images beneath cen-tral Cascadia show that subducting seamount may be responsible for seismic activity (Trhu et al.,2012).
According to the hypocenter of megathrust earthquakes in Tohoku 2011, it lies in the vicinityof seamount area, and perhaps there is a likelihood of subducting seamount (Wang and Bilek, 2014).Apart from the fact that there are two opinions about the effect of subducting seamount, themechanical process of overriding plate in subduction zone is very complex and lack of geophysicalimages. Therefore, in this report we will review the previous study and challenges of followingresearch. Also attempt to obtain a proper answer for the effect of subducting seamount.