Quake clamps down on slow slip

TitleQuake clamps down on slow slip
Publication TypeJournal Article
Year of Publication2014
AuthorsWallace L.M, Bartlow N., Hamling I., Fry B.
JournalGeophysical Research Letters
Date Published2014/12
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000348916500022
Keywordsdeformation; earthquakes; events; friction; New Zealand; new-zealand; sequence; slow slip events; stress change; stress transfer; subduction; subduction zone; tohoku-oki earthquake

Using continuous GPS (cGPS) data from the Hikurangi subduction zone in New Zealand, we show for the first time that stress changes induced by a local earthquake can arrest an ongoing slow slip event (SSE). The cGPS data show that the slip rate in the northern portion of the 2013/2014 Kapiti SSE decreased abruptly following a nearby intraslab earthquake. We suggest that deceleration of the Kapiti SSE in early 2014 occurred due to a tenfold increase in the normal stress relative to shear stress in the SSE source, induced by the nearby M-w 6.3 earthquake, consistent with expectations of rate and state friction. Our observation of an abrupt halting/slowing of the SSE in response to stress changes imposed by a local earthquake has implications for the strength of fault zones hosting SSEs and supports the premise that static stress changes are an important ingredient in triggering (or delaying) fault slip.

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