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.

This open access book explores the interactions between water and earthquakes, including recent concerns about induced seismicity. It further highlights that a better understanding of the response of the water system to disturbances such as earthquakes is needed to safeguard water resources, to shield underground waste repositories, and to mitigate groundwater contamination. Although the effects of earthquakes on streams and groundwater have been reported for thousands of years, this field has only blossomed into an active area of research in the last twenty years after quantitative and continuous documentation of field data became available. This volume gathers the important advances that have been made in the field over the past decade, which to date have been scattered in the form of research articles in various scientific journals.

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.