Compelling evidence of an aseismic slab beneath central Taiwan from a dense linear seismic array

From a dense linear seismic array consisting of 15 short-period seismic stations deployed across the suture zone, an aseismic slab subducted beneath central Taiwan was clearly detected. In addition to the direct P-waves, the identification of the mantle refracted phases generated by an intermediate-depth earthquake (ML = 5.8) in southeastern Taiwan and recorded by the linear array as well as some seismic stations (CWBSN) along the Eastern Central Range shows that a subducted crust with a low velocity exists down at the depth of at least 89 km. This strongly suggests that the subduction of the Eurasian plate in southern Taiwan most likely extends to central Taiwan, where there has been an absence of mantle earthquakes in the Wadati-Benioff zone. What the subduction slab without mantle earthquakes could very well be attributed to is the subducted continental crust, where the rock strength is totally different from that of the oceanic crust.