Downloads: 5

Files in This Item:
File Description SizeFormat 
2006GL026507.pdf1.36 MBAdobe PDFView/Open
Title: Small slow-strain steps and their forerunners observed in gold mine in South Africa
Authors: Naoi, Makoto  kyouindb  KAKEN_id  orcid (unconfirmed)
Ogasawara, Hiroshi
Takeuchi, Junichi
Yamamoto, Akihito
Shimoda, Naoyuki
Morishita, Ken
Ishii, Hiroshi
Nakao, Shigeru
van Aswegen, Gerrie
Mendecki, Aleksander J.
Lenegan, Patrick
Ebrahim-Trollope, Rookshana
Iio, Yoshihisa  kyouindb  KAKEN_id  orcid (unconfirmed)
Author's alias: 直井, 誠
飯尾, 能久
Issue Date: 23-Jun-2006
Publisher: American Geophysical Union
Journal title: Geophysical Research Letters
Volume: 33
Issue: 12
Thesis number: L12304
Abstract: The Research Group for Semi-controlled Earthquake-generation Experiments in South African deep gold mines (SeeSA) has continuously monitored strain changes with a resolution of 24 bit 25 Hz at the Bambanani mine near Welkom. An Ishii borehole strainmeter was installed at a depth of 2.4 km near the potential M ∼ 3 earthquake source area. Instantaneous strain steps of ∼10−4 strains associated with two M2 events were observed within a length of seismic fault. These steps were followed by significant post-seismic creep-like drift, but not preceded by forerunners. Analysis of the continuous 25 Hz data reveals many smaller steps with much longer durations (100 ms ∼ 100 s) than seen in normal earthquakes (−1 < M < 2) with source durations of 1 ms∼50 ms. Some of the especially slow steps were preceded by accelerations in strain, the maximum being as large as one-third of the step.
Rights: © 2006 by the American Geophysical Union
The full-text file will be made open to the public on 23 December 2006 in accordance with publisher's 'Terms and Conditions for Self-Archiving'
DOI(Published Version): 10.1029/2006GL026507
Appears in Collections:Journal Articles

Show full item record

Export to RefWorks

Export Format: 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.