Deep structure of the Racha earthquake source zone from seismic tomography data

2006 ◽  
Vol 42 (1) ◽  
pp. 27-40 ◽  
Author(s):  
S. S. Arefiev ◽  
E. A. Rogozhin ◽  
V. V. Bykova ◽  
C. Dorbath
Geophysics ◽  
1989 ◽  
Vol 54 (5) ◽  
pp. 570-580 ◽  
Author(s):  
Keith A. Meyerholtz ◽  
Gary L. Pavlis ◽  
Sally A. Szpakowski

This paper introduces convolutional quelling as a technique to improve imaging of seismic tomography data. We show the result amounts to a special type of damped, weighted, least‐squares solution. This insight allows us to implement the technique in a practical manner using a sparse matrix, conjugate gradient equation solver. We applied the algorithm to synthetic data using an eight nearest‐neighbor smoothing filter for the quelling. The results were found to be superior to a simple, least‐squares solution because convolutional quelling suppresses side bands in the resolving function that lead to imaging artifacts.


2013 ◽  
Vol 5 (2) ◽  
pp. 1687-1720 ◽  
Author(s):  
L. T. White ◽  
M. P. Morse ◽  
G. S. Lister

Abstract. The location of major Cu-Au deposits on the island of New Guinea are considered to be controlled by a series of transfer faults that strike N–S to NE–SW, perpendicular to the long axis of the island. The premise is that these faults dilate perpendicular to the regional stress field, forming conduits for metalliferous bearing fluids and gas to deposit. However, the data on which this idea was first proposed was often not presented, or when it was, is of poor quality or low resolution. We therefore present a review of the existing structural interpretations and compare these with several recently published geophysical datasets (gravity, magnetics and seismic tomography) to determine if the Cu-Au controlling transfer faults could be observed. These data were used to produce a new lineament map of New Guinea. A comparison of the lineaments with the location of major Cu-Au deposits indicates there is a link between the arc-normal structures and mineralization. However, it is only those deposits that are less than 4.5 million years old that could be associated with these structures. Gravity and seismic tomography data indicate that some of these structures could penetrate deep levels of the lithosphere, providing some support to the earlier idea that the arc-normal transfer faults act as conduits for the younger mineral deposits of New Guinea. The gravity data can also be used to infer the location of igneous intrusions at depth, which could have brought metal-bearing fluids and gases closer to the Earth's surface. These regions might be of interest for future exploration campaigns, particularly those areas that are crosscut by deep, vertical faults. However, new exploration models are needed to explain the location of the deposits that are older than 5 Ma.


2016 ◽  
Vol 679 ◽  
pp. 235-245 ◽  
Author(s):  
Giovanni Camanni ◽  
Joaquina Alvarez-Marron ◽  
Dennis Brown ◽  
Concepcion Ayala ◽  
Yih-Min Wu ◽  
...  

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