Lateral Variations of the Mantle Transition Zone Structure beneath Eastern China

Abstract

The mantle transition zone (MTZ) structure beneath eastern China is studied by using P-wave receiver functions. The 410 km discontinuity is relatively flat whereas the depth of the 660 km discontinuity varies significantly under the study area. This indicates that the 660 is more influenced by laterally varying temperature. The 520 km discontinuity is continuously observed at ∼520 km depth under a limited area. Within the South China Block, the MTZ thickness under the Yangtze Craton is larger than normal whereas that under the Cathaysia Block is nearly normal. This indicates colder temperature affecting the MTZ beneath the Yangtze Craton. Combined with seismic tomography, our result suggests that the stagnant ancient slab beneath eastern China is mainly trapped around the base of the MTZ beneath the Yangtze Craton in the study area.

Investigating the Groningen gas reservoir: From passive seismic monitoring to experiments on effects of pore pressure on fault slip

“…In the seismological community, the receiver function method has been widely used to image subsurface discontinuities such as the Moho (e.g., Langston, 1979;Xu et al, 2007), mantle discontinuities (e.g., Huang et al, 2014;Vinnik, 1977) and a subducting slab interface (e.g., Cheng et al, 2017;Paulssen & De Vos, 2017), usually employing incident P waves from teleseismic earthquakes. The receiver function method is not, or least not commonly, used by the exploration seismology community.…”

“…Although the number of events above the reservoir is relatively small, they indicate that the overburden is deforming by unstable slip. Moreover, experimental work by Hunfeld et al (2017) on anhydrite samples from the Groningen subsurface shows that they exhibit a velocity-weakening behavior (i.e. decreasing frictional resistance with increasing sliding velocity), implying that anhydrite is capable of nucleating earthquakes.…”