Long-period ocean-bottom motions in the source areas of large subduction earthquakes

Long-period ocean-bottom motions in the source areas of large subduction earthquakes

Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evide...

Systematic deficiency of aftershocks in areas of high coseismic slip for large subduction zone earthquakes

Fault slip during plate boundary earthquakes releases a portion of the shear stress accumulated due to frictional resistance to relative plate motions. Investigation of 101 large [moment magnitude (Mw) ≥ 7] subduction zone plate boundary mainshocks with consistently determined coseismic slip distributions establishes that 15 to 55% of all master event-relocated aftershocks with Mw ≥ 5.2 are loc...

Depths of Large Earthquakes Determined From Long-Period Rayleigh Waves

The depths and source mechanisms of nine large shallow earthquakes were determined from long-period (150 to 300 s) Rayleigh waves recorded by the Global Digital Seismograph Network (GDSN) and International Deployment of Accelerometers (IDA) networks. We inverted the data set of complex source spectra for a moment tensor (linear) or a double couple (nonlinear). By solving a least squares problem...

Generation Mechanism of Giant Earthquakes in Subduction Zones with Smaller-Size Interplate Earthquakes During Interseismic Period

Temporal variation of large intraplate earthquakes in coupled subduction zones

The focal mechanisms of intraplate earthquakes within subducting lithosphere are frequently used to infer large-scale stress regimes induced by slab-pull, bending or unbending, and lateral segmentation and undulations of the slab . Numerous studies have further postulated that the intraplate activity is influenced by transitory regional stress regimes such as those associated with interplate th...