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Tectonic tremor and deep slow slip on the Alpine Fault

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journal contribution
posted on 09.02.2021, 19:11 by A Wech, C Boese, Timothy Stern, John Townend
Tectonic tremor is characterized by persistent, low-frequency seismic energy seen at major plate boundaries. Although predominantly associated with subduction zones, tremor also occurs along the deep extension of the strike-slip San Andreas Fault. Here we present the first observations of tectonic tremor along New Zealand's Alpine Fault, a major transform boundary that is late in its earthquake cycle. We report tectonic tremor that occurred on the central section of the Alpine Fault on 12days between March 2009 and October 2011. Tremor hypocenters concentrate in the lower crust at the downdip projection of the Alpine Fault; coincide with a zone of high P-wave attenuation (low Q p) and bright seismic reflections; occur in the 25-45km depth range, below the seismogenic zone; and may define the deep plate boundary structure extending through the lower crust and into the upper mantle. We infer this tremor to represent slow slip on the deep extent of the Alpine Fault in a fluid-rich region marked by high attenuation and reflectivity. These observations provide the first indication of present-day displacement on the lower crustal portion of the Australia-Pacific transform plate boundary. © Copyright 2012 by the American Geophysical Union.

History

Preferred citation

Wech, A., Boese, C., Stern, T. & Townend, J. (2012). Tectonic tremor and deep slow slip on the Alpine Fault. Geophysical Research Letters, 39(10), 1-6. https://doi.org/10.1029/2012GL051751

Journal title

Geophysical Research Letters

Volume

39

Issue

10

Publication date

01/01/2012

Pagination

1-6 (6)

Publisher

American Geophysical Union (AGU)

Publication status

Published

Contribution type

Article

Online publication date

19/05/2012

ISSN

0094-8276

Article number

ARTN L10303

Language

en

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