TY  - JOUR
A1  - Mohr, Christian Heinrich
A1  - Manga, Michael
A1  - Wang, Chi-Yuen
A1  - Korup, Oliver
T1  - Regional changes in streamflow after a megathrust earthquake
JF  - Earth & planetary science letters
N2  - Moderate to large earthquakes can increase the amount of water feeding stream flows, mobilizing excess water from deep groundwater, shallow groundwater, or the vadose zone. Here we examine the regional pattern of streamflow response to the Maule M8.8 earthquake across Chile's diverse topographic and hydro-climatic gradients. We combine streamflow analyses with groundwater flow modeling and a random forest classifier, and find that, after the earthquake, at least 85 streams had a change in flow. Discharge mostly increased () shortly after the earthquake, liberating an excess water volume of >1.1 km3, which is the largest ever reported following an earthquake. Several catchments had increased discharge of >50 mm, locally exceeding seasonal streamflow discharge under undisturbed conditions. Our modeling results favor enhanced vertical permeability induced by dynamic strain as the most probable process explaining the observed changes at the regional scale. Supporting this interpretation, our random forest classification identifies peak ground velocity and elevation extremes as most important for predicting streamflow response. Given the mean recurrence interval of ∼25 yr for >M8.0 earthquakes along the Peru–Chile Trench, our observations highlight the role of earthquakes in the regional water cycle, especially in arid environments.
KW  - Maule earthquake
KW  - streamflow response
KW  - permeability
KW  - groundwater flow modeling
KW  - earthquake hydrology
Y1  - 2016
U6  - https://doi.org/10.1016/j.epsl.2016.11.013
SN  - 0012-821X
SN  - 1385-013X
VL  - 458
SP  - 418
EP  - 428
PB  - Elsevier
CY  - Amsterdam
ER  -