Clustering of offsets on the Haiyuan fault and their relationship to paleoearthquakes

Abstract

We used airborne light detection and ranging (LiDAR) data to reevaluate the singleevent offsets of the 1920 Haiyuan Ms 8.5 earthquake and the cumulative offsets along the western and middle segments of the coseismic surface rupture zone. Our LiDAR data indicate that the offset observations along both the western and middle segments fall into groups. The group with the minimum slip amount is associated with the 1920 Haiyuan Ms 8.5 earthquake, which ruptured both the western and middle segments. Our research highlights two new interpretations: First, the previously reported maximum displacement of the 1920 earthquake was likely due to at least two earthquakes; second, our results reveal that the cumulative offset probability density (COPD) peaks of the same offset amounts on the western and middle segments do not correspond to one another one-to-one. We suggest that any discussion of the rupture pattern of a certain fault based on the offset data should also consider fault segmentation and paleoseismological data. Therefore, the COPD peaks should be computed and analyzed on fault subsections and not entire fault zones to study the number of paleoearthquakes and their rupture patterns.

Crustal Deformation in the India‐Eurasia Collision Zone From 25 Years of GPS Measurements

“…It has remained unbroken for ~1000 years (Liu‐Zeng et al, ), except for some moderate events such as the 2016 M w 5.9 Menyuan earthquake (Wang, Liu‐Zeng, et al, ). Our data show deformation consistent with elastic strain accumulation in this region (profile HY1 in Figure e); the accumulated slip deficit in the Tianzhu gap since ~1000 is now about 4.3 m. This is within 1 sigma error of the ~5 m coseismic slip of the Haiyuan earthquake from the recent LiDAR study by Ren et al ().…”

Paleoearthquakes and Rupture Behavior of the Lenglongling Fault: Implications for Seismic Hazards of the Northeastern Margin of the Tibetan Plateau

“…For example, Liu‐Zeng et al () revealed that the four large earthquakes that occurred in the past 3500–3900 years along the Laohushan fault had an average recurrence interval of ~1,000 years. P. Z. Zhang et al () and Ren et al () found that the Haiyuan fault may rupture in segments. Liu‐Zeng et al () identified three or four seismic events on the Haiyuan fault since A.D. 1500 based on trench and historical records.…”

“…P. Z. Zhang et al (2005) and Ren et al (2015) found that the Haiyuan fault may rupture in segments. Liu-Zeng et al (2015) identified three or four seismic events on the Haiyuan fault since A.D. 1500 based on trench and historical records.…”

The Longriqu fault zone, eastern Tibetan Plateau: Segmentation and Holocene behavior

“…Several studies show that multiscale displacement inventories allow to decipher single-event slip from cumulative displacements [e.g., Barka, 1996;van der Woerd et al, 2002;Zielke et al, 2010Zielke et al, , 2015Klinger et al, 2011]. Moreover, the along-strike fault cumulative displacement pattern can constrain whether or not fault segments are independently rupturing during earthquakes [e.g., Schwartz and Coppersmith, 1984;Klinger et al, 2005;Ren et al, 2015]. Such information on geometrical and displacement characteristics of faults is important to derive generic properties and improve our understanding of rupture process and seismic cycle [e.g., Wesnousky, 2008;Manighetti et al, 2005].…”