Distantearthquakesarewellknowntoinduceawiderangeofresponsesinsurface
water and groundwater. These responses are often viewed as mere
curiositiesas
theiroccurrenceislimitedinspaceandtime.Thefrequentemphasisonearthquake
precursorsinstudiesofthesephenomenaalsotendstopushthestudyof'earthquake
hydrology' away from the mainstream of geoscience. The observed
phenomena, however,
probetheinteractionbetweenhydrogeologicalprocessesandmechanical
deformationintheshallowcrust.Hencetheyprovideinsightintotheinteraction
among water cycle, tectonics, and properties of the crust. As such, the
study of
earthquakehydrologyalsohasthepotentialtoprovideamorequantitativeand-
depthunderstandingofthenatureofearthquakeprecursorsandevaluatewhether
theyareinfactprecursors. The title of this book re ects the nature of
the connections we address: we focus on how earthquakes affect
hydrology. Water also in uences earthquakes as it affects the strength
of faults and the rheology of rocks. Our emphasis here, however, is not
on the hydrology of earthquakes, but on understanding the hydrological
phenomena induced or modi ed by earthquakes. The boundary
betweenthe'hydrologyofearthquakes'andthe'earthquake-inducedhydrological
phenomena', however, can sometimes be blurred. For example, triggered
ear- quakes are sometimes explained by a re-distribution of pore
pressure following the triggering earthquake. Hence, triggered
seismicity may be an example of an earthquake-induced hydrological
phenomenon. Thestudyofthelatter, therefore,
canbeimportanttowardsabetterunderstandingofthemechanicsofatleastsome
earthquakes. Therearemanystudents,
postdocsandcolleagueswewishtothankforcolla-
ratingonresearchprojectsrelatedtothetopicsreviewedinthisbook,
orparticip-
inginstimulatingdiscussionsintheclasswetaughtcalled'Earthquakehydrology'.
In particular, we wish to thank Emily Brodsky, Yeeping Chia, Douglas
Dreger, Shemin Ge, Fu-qiong Huang, Tom Holzer, Chris Huber, Joel
Rowland, Martin Saar, Yaolin Shi, Chung-Ho Wang, Kelin Wang, Pei-ling
Wang and Alex Wong forenlighteningexchanges.HunterPhilsonhelpedwith
guresandtheindex.We v vi Preface alsothanktheNationalScienceFoundation,
theMillerInstituteforBasicResearch inScience,
andNASAforsupportingtheresearchandsynthesisinthisvolume.
