Comparative Study on the Deviation Characteristics of Post-Earthquake Intensity Evaluation Based on Two Intensity Attenuation Relationship Models

Arias Intensity Attenuation Relationship in Sichuan-yunnan Region, China

10.21203/rs.3.rs-1129750/v1 ◽

2021 ◽

Author(s):

Ping Liu ◽

Tongjie Ren

Keyword(s):

Site Effects ◽

Strong Motion ◽

Attenuation Relationship ◽

Intensity Measure ◽

Arias Intensity ◽

Intensity Attenuation ◽

Yunnan Region ◽

High Incidence ◽

Average Shear ◽

Basin Effects

Abstract Arias intensity is an essential ground motion measure correlating with the potential for earthquake-induced landslides. The Sichuan-Yunnan region, which is primarily mountainous, is a high incidence region of earthquake-induced landslides in China. However, there is no available attenuation relationship for this intensity measure due to the backward construction of the stations. In this study, we developed a region-specific Arias intensity attenuation relationship using the China Strong-Motion Networks Center (CSMNC) database which was established in 2008. We recommend this relationship be applied in the Sichuan-Yunnan region for moment magnitudes ranging between 4.2 and 7.9, distances ranging between 0 and 400 km and with Vs30 (the average shear-wave velocity in the upper 30 meters of a soil profile) ranging between 128 and 760 m/s. The current study finds that this relationship’s intra-event, inter-event, and total standard deviations are greater than for other regions. This is likely caused by the complicated seismotectonic activities, nonlinear site effects, error from inferring Vs30, basin effects, etc. However, this relationship has the best performance in fitting and predicting the data from the Sichuan-Yunnan region.

Download Full-text

A real-time prediction model for macroseismic intensity in China

Journal of Seismology ◽

10.1007/s10950-020-09965-w ◽

2020 ◽

Author(s):

Xu Weixiao ◽

Yang Weisong ◽

Yu Dehu

Keyword(s):

Intensity Distribution ◽

Rapid Assessment ◽

Semimajor Axis ◽

Focal Depth ◽

Assessment Method ◽

Macroseismic Intensity ◽

Lms Algorithm ◽

Attenuation Relationship ◽

Intensity Attenuation ◽

Isoseismal Lines

Abstract The macroseismic intensity spatial distribution is an important input for most rapid loss modeling and emergency work. Data from a total of 175 earthquakes (Ms ≥ 5.0) in China from 1966 to 2014 were collected, and the rapid assessment method of macroseismic intensity distribution was studied. First, simple relationships among the epicentral intensity, magnitude, and focal depth were established. A greater amount of database is used in this study than that in a previous work (Fu and Liu in Sci R 4(5): 350-354 (1960), Mei in Chin J Geophys 9(1): 1–18 (1960), and Yan et al. in Sci Chin 11: 1050-1058 (1984)), and the studied earthquakes all occurred in the last 50 years, providing more accurate and uniform parameter information. As the seismic intensity-attenuation relationship is traditionally used to estimate the intensity distribution, the macroseismic intensity-attenuation relationship for mainland China was fitted by the earthquake data collected in this region. The deviation of the intensity assessment by the macroseismic intensity-attenuation relationship was examined for 43 earthquakes (Ms ≥ 6.0). In addition, seismic damage emergency assessment work requires the isoseismal lines to be constantly modified according to the updated information. Therefore, an improved ellipse intensity-attenuation model was proposed in this study, completed by the establishment of a semimajor axis and semiminor axis length matrix. Based on the initial value of the length matrix obtained by the regression of historical data and survey data from the site, the least mean squares (LMS) algorithm is used to revise the length matrix. In the end, the practicability of this method is verified by a case study of the Lijiang 7.0 earthquake.

Download Full-text