Abstract
Earthquake recurrence models assume that major surface-rupturing earthquakes are followed by periods of reduced rupture probability as stress rebuilds. Although purely periodic, time- or slip-predictable rupture models are known to be oversimplifications, a paucity of long records of fault slip clouds understanding of fault behavior and earthquake recurrence over multiple ruptures. Here, we report a 16 kyr history of fault slip including a pulse of accelerated slip from 6.4 to 6.0 ka-determined using a Monte Carlo analysis of well-dated offset landforms along the central Altyn Tagh strike-slip fault (ATF) in northwest China. This pulse punctuates a median rate of 8.1(+1.2) /-0.9 mm/a and likely resulted from either a flurry of temporally clustered similar to Mw 7.5 ground-rupturing earthquakes or a single large >Mw 8.2 earthquake. The clustered earthquake scenario implies rapid re-rupture of a fault reach > 195 km long and indicates decoupled rates of elastic strain energy accumulation versus dissipation, conceptualized as a crustal stress battery. If the pulse reflects a single event, slip-magnitude scaling implies that it ruptured much of the ATF with slip similar to, or exceeding, the largest documented historical ruptures. Both scenarios indicate fault rupture behavior that deviates from classic time- or slip-predictable models. Published by Elsevier B.V.
Item Type: | Journal article |
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Faculties: | Geosciences > Department of Earth and Environmental Sciences |
Subjects: | 500 Science > 550 Earth sciences and geology |
ISSN: | 0012-821X |
Language: | English |
Item ID: | 55959 |
Date Deposited: | 14. Jun 2018, 10:00 |
Last Modified: | 04. Nov 2020, 13:36 |