A new insight into the sources of the 1733DC-M7.8 earthquake on the
Xiaojiang fault zone, southeastern Tibet
Abstract
As early as in 1733, an M~7.8 earthquake (1733DC-M7.8
earthquake) ruptured the 110km-long northern segment of the Xiaojiang
fault zone, on the southeastern boundary of Tibetan plateau, and 100
years later, in 1833, another M~8.0 earthquake
(1833SM-M8.0 earthquake) broke the 130 km-long middle segment. Here we
show a new insight into the source of the 1733DC-M7.8 earthquake through
the latest regional GNSS measurements plus our near-fault seismic and
GNSS observations since February 2012. An inversion of the regional GNSS
measurements resolved an asperity for the 1733DC-M7.8 earthquake that is
bearing more slip deficit in comparison with the 1833SM-M8.0 earthquake,
implying an Mw7.2+ earthquake, and the near-fault GNSS and seismic
observations not only justified this asperity with localized deformation
and multi-scaled seismicity but also are declaring an impending rupture
of the asperity. More importantly, this work contributes a typical
example to the recently proposed model for the generation of large
earthquakes.