Open AccessSlow tilt reversal of the Lesser Himalaya between 1862 and 1992 at 78°E, and bounds to the southeast rupture of the 1905 Kangra earthquake
Author(s) -
Bilham Roger
Publication year - 2001
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1046/j.1365-246x.2001.01365.x
Subject(s) - geology , levelling , seismology , tilt (camera) , geodesy , slip (aerodynamics) , geometry , physics , mathematics , thermodynamics
Summary Measurements between 1862 and 1992 of a 77‐km‐long spirit levelling line that crosses the main frontal thrust of the Himalaya near Dehra Dun (78°E) reveal a slow reversal of tilt in the early part of the last century, unperturbed by the destructive 1905 April 4 Kangra earthquake, 200 km to the northwest. The Lesser Himalaya are inferred to be tilting currently to the northeast at 0.08 µrad yr −1 , with similar rate but opposite sign to their tilt in 1862. The absence of co‐seismic deformation near Dehra Dun in 1905 indicates that the Kangra rupture terminated short of Dehra Dun, consistent with a revised M s = 7.8 estimate for the size of the Kangra earthquake, but inconsistent with previous analyses of the levelling data that interpret a large slope‐dependent systematic error as co‐seismic slip. The reversal in tilt corresponds to a linear northeast‐down tilt acceleration of 0.0015 ± 0.0004 µrad yr −2 .