Crustal Structures Revealed by Seismic Interfrometry Beneath the North China Craton and Central Asian Orogenic Belt

Session: Waveform Cross-Correlation-Based Methods in Observational Seismology [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

By applying seismic interferometry to a dense seismic profile (NCISP-6), we get the P-wave reflection structures beneath the northern North China Craton (NCC) and eastern Central Asian Orogenic Belt (CAOB). The dense seismic array extended southeast to northwest for about 920 km with a spacing of 10-17 km from the China-North Korea border to the Sino-Mongolian border and was deployed by the Institute of Geology and Geophysics, Chinese Academy of Sciences. The method global phase seismic interferometry (GloPSI) suggests the autocorrelation of PKIKP phase and its coda can be used to imaging crustal structures, so the events with epicentral distances > 120° are used. To employ enough events, the method seismic daylight imaging (SDI) suggests the events with epicentral distances greater than 30° and less than 90° also can be used. In this study, we utilized the two methods and selected 14 events for GloPSI and 93 events for SDI. The major processing steps are as follows: instruments response removal, bandpass filter, autocorrelation, spectral balancing, moveout correction, jackkniffing, stack, average source time function removal, multiples removal, elevation correction, bilinearly interpolation and time-to-depth conversion. The Moho and mid-lithosphere discontinuities (MLD) are clear in the final images and the images of GloPSI and SDI have good consistency. The depth of Moho below the northern NCC is about 40 km which similar to the result of receiver function, but the depth of Moho below the eastern CAOB has some difference the result of receiver function. We guess that the structures below the transitional zone of eastern CAOB and northern NCC is more complicit than the structures revealed by receiver function before. The depth of MLD is about 85 km and nearly horizontal below this area The result agreed with other researches and geological settings in this area. It provides the P-wave reflection structures and even higher resolution than receiver function. It may help to some geological problems at particular areas.

Presenting Author: Jinju Zhou

Authors