Imaging the heterogeneous source area of the 2003 M6.4 northern Miyagi earthquake, NE Japan, by double-difference tomography

2007 ◽  
Vol 430 (1-4) ◽  
pp. 67-81 ◽  
Author(s):  
Tomomi Okada ◽  
Akira Hasegawa ◽  
Jun'ichi Suganomata ◽  
Norihito Umino ◽  
Haijiang Zhang ◽  
...  
Keyword(s):  
Source Area ◽  
Double Difference ◽  
Heterogeneous Source ◽  
Ne Japan

scholarly journals Relocation of Intermediate-depth Earthquakes beneath the NE Japan Arc by Double-Difference Location Method

2006 ◽  
Vol 59 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Junichi SUGANOMATA ◽  
Tomomi OKADA ◽  
Akira HASEGAWA ◽  
Koji SAKODA ◽  
Stephen H. KIRBY
Keyword(s):  
Double Difference ◽  
Intermediate Depth ◽  
Location Method ◽  
Ne Japan

3D Crustal Structure and Seismicity Characteristics of Changning–Xingwen Area in the Southwestern Sichuan Basin, China

2020 ◽  
Vol 110 (5) ◽  
pp. 2154-2167 ◽  
Author(s):  
Kezhen Zuo ◽  
Cuiping Zhao ◽  
Haijiang Zhang
Keyword(s):  
Sichuan Basin ◽  
Source Area ◽  
Double Difference ◽  
Small Scale ◽  
Low Velocity ◽  
Aftershock Activity ◽  
Velocity Anomaly ◽  
Crustal Structures ◽  
The Sichuan Basin ◽  
Tomography Method

ABSTRACT Using seismic data recorded on permanent and temporary stations around the Changning area in the Sichuan basin, the high-resolution 3D crustal VP, VS, VP/VS models and earthquake locations in the Changning–Xingwen area are obtained using the VP/VS model consistency-constrained double-difference seismic tomography method. The results show that crustal structures in the source area of the 2019 Ms 6.0 Changning earthquake have significant variations, especially in the depth of 0–7 km. Seismic activity in the Shuanghe and Yutan anticline areas before the Ms 6.0 Changning earthquake outlined several northeast-trending stripes, implying pre-existing small-scale faults that are perpendicular to the major northwest-striking faults in the Changning–Shuanghe anticline system. We found that the Ms 6.0 Changning earthquake broke through these pre-existing small-scale faults and extended from the Shuanghe to the Yutan anticlines. Both the rupture process and aftershock activity were influenced by the pre-existing small-scale faults. Most earthquakes within the Changning area are located in a slant zone that gradually deepens from the Shuanghe anticline on the east to the Yutan anticline on the west with the maximum depth from 5 to 10 km, which are associated with obvious high-VS and low-VP/VS features. The relocated seismic clusters in the Luochang–Jianwu syncline area have different strikes and dips, which are mainly located at the edge of low-velocity anomaly bodies and correspond to the low-VP/VS area.

Imaging the source area of the 1995 southern Hyogo (Kobe) earthquake (M7.3) using double-difference tomography

2007 ◽  
Vol 253 (1-2) ◽  
pp. 143-150 ◽  
Author(s):  
T. Okada ◽  
A. Hasegawa ◽  
J. Suganomata ◽  
D. Zhao ◽  
H. Zhang ◽  
...  
Keyword(s):  
Source Area ◽  
Double Difference ◽  
Kobe Earthquake

Permo-Carboniferous sediments at Kraskov (borehole KS-1) and their source area

2015 ◽  
Author(s):  
Marcela Stárková ◽  
Štěpánka Mrázová ◽  
Tamara Sidorinová
Keyword(s):  
Source Area

The Distribution of Volatile Organics in a Leachate Plume, Gloucester, Ontario

1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman
Keyword(s):  
Organic Contaminants ◽  
Source Area ◽  
Unconfined Aquifer ◽  
High Concentration ◽  
Organic Contamination ◽  
Aquifer System ◽  
Aquifer Systems ◽  
Volatile Organic ◽  
Volatile Organic Contaminants ◽  
Aquifer Sediments

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.

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