Seismology Observations on the 21 March 2019 Accidental Explosion at Xiangshui Chemical Plant in Jiangsu, China

Session: Explosion Seismology Advances
Type: Oral
Date: 4/29/2020
Time: 09:00 AM
Room: 240
Description: 

On 21 March 2019, an explosion accidentally occurred at a chemical plant in Yancheng, Jiangsu province, China. According to the quick report from the China Earthquake Network Center (CENC), the explosion had a local magnitude M_L 2.2, occurred at 14:48 local time (06:48 GMT) and with an epicenter 34.334°N 119.776°E. Seismograms generated by the explosion are collected from broadband seismic stations affiliated with the China Digital Seismic Network (CDSN) and the Global Seismic Network (GSN). For this explosion, as well as for 4 other nearby earthquakes, both body-wave and surface-wave magnitudes are calculated based on the Lg and Rayleigh waves. The magnitudes of the explosion are m_b(Lg)=3.50±0.17 and Ms=1.76±0.35, respectively. Compared to nearby earthquakes, the mb(Lg)-Ms method does not discriminate the known explosion from the earthquake. If we adopt the fully coupled hard-rock site equation by Bowers et al. (2001), the explosion yield can be estimated from the Lg-wave magnitude as approximately 100 ton TNT equivalent, with an uncertainty ranging between 60 and 170 ton. However, based on the crater size, the estimated yield is 272 ton TNT equivalent. Assuming that the explosive energy of the nitration waste equals to 0.3-0.5 TNT equivalent, the above estimations roughly reflected the actual amount of material involved in the explosion. The apparently lower yield value obtained from seismic data compared to those from ground truth is partially resulted from that the empirical magnitude-yield equation is for fully buried explosions, while the studied event is an open pit explosion, which has lower conversion rate in exciting seismic waves. For an open pit explosion, the explosion to seismic energy conversion rate can be revealed to be about one third compared to that from a buried explosion. This work was supported by the National Natural Science Foundation of China (41674060, 41630210 and 41974054) and the Special Fund of China Seismic Experimental Site (2019CSES0103).

Presenting Author: Lian-Feng Zhao

Authors