Microseismicity and P-wave tomography of the central Alpine Fault, New Zealand

被引：11

作者：

Feenstra, J. ^{[1
]}

Thurber, C. ^{[1
]}

Townend, J. ^{[2
]}

Roecker, S. ^{[3
]}

Bannister, S. ^{[4
]}

Boese, C. ^{[5
]}

Lord, N. ^{[1
]}

Bourguignon, S. ^{[4
]}

Eberhart-Phillips, D. ^{[4
,6
]}

机构：

[1] Univ Wisconsin, Dept Geosci, Madison, WI 53706 USA

[2] Victoria Univ Wellington, Sch Geog Environm & Earth Sci, Wellington, New Zealand

[3] Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY USA

[4] GNS Sci, Lower Hutt, New Zealand

[5] Int Earth Sci IESE Ltd, Auckland, New Zealand

[6] Univ Calif Davis, Dept Earth & Planetary Sci, Davis, CA 95616 USA

来源：

NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS | 2016年 / 59卷 / 04期

基金：

美国国家科学基金会;

关键词：

Alpine Fault; deep fault drilling project; New Zealand; tomography; seismogenic zone; CENTRAL SOUTH-ISLAND; PLATE-BOUNDARY; LITHOSPHERIC STRUCTURE; EARTHQUAKES OCCUR; FOCAL MECHANISMS; HAYWARD FAULT; SLIP RATE; ALPS; ZONE; SEISMICITY;

D O I：

10.1080/00288306.2016.1182561

中图分类号：

P5 [地质学];

学科分类号：

0709 ; 081803 ;

摘要：

We utilise seismic data from the central section of the Alpine Fault to locate earthquakes and image crustal structure in three dimensions. Tomography results from c. 6500 sources reveal the fault as either a southeast-dipping low-velocity zone or a marked velocity contrast in different parts of the study region. Where our model is best resolved, we interpret the Alpine Fault to be listric in nature, dipping steeply in the upper crust (50-60 degrees) and flattening to 25-30 degrees in the lower crust. The base of the seismogenic zone shallows from c. 15km beneath the footwall and Alpine Fault to c. 6km beneath the Southern Alps Main Divide, and then deepens to c. 15km by c. 10km further southeast. The shallow brittle-ductile transition overlies a broad low-velocity zone, which together likely result from the presence of fluids and elevated temperatures brought about by enhanced exhumation rate in this section of the Alpine Fault.

引用

页码：483 / 495

页数：13