Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Other style
More styles
Language
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Other locale
More languages
Output format
• html
• text
• asciidoc
• rtf
A Strategy for Earthquake Catalog Relocations Using a Maximum Likelihood Method:
Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
2012 (English)Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesisAlternative title

:
##### Abstract [en]

A strategy for relocating earthquakes in a catalog is presented. The strategy is based on the argument that the distribution of the earthquake events in a catalog is reasonable a priori information for earthquake relocation in that region. This argument can be implemented using the method of maximum likelihood for arrival time data inversion, where the a priori probability distribution of the event locations is defined as the sum of the probability densities of all events in the catalog. This a priori distribution is then added to the standard misfit criterion in earthquake location to form the likelihood function. The probability density of an event in the catalog is described by a Gaussian probability density. The a priori probability distribution is, therefore, defined as the normalized sum of the Gaussian probability densities of all events in the catalog, excluding the event being relocated. For a linear problem, the likelihood function can be approximated by the joint probability density of the a priori distribution and the distribution of an unconstrained location due to the misfit alone. After relocating the events according to the maximum of the likelihood function, a modified distribution of events is generated. This distribution should be more densely clustered than before in general since the events are moved towards the maximum of the posterior distribution. The a priori distribution is updated and the process is iterated. The strategy is applied to the aftershock sequence in southwest Iceland after a pair of earthquakes on 29th May 2008. The relocated events reveal the fault systems in that area. Three synthetic data sets are used to test the general behaviour of the strategy. It is observed that the synthetic data give significantly different behaviour from the real data.

2012. , 45 p.
##### Series
Examensarbete vid Institutionen för geovetenskaper, ISSN 1650-6553 ; 250
##### Keyword [en]
earthquake catalog, relocation, maximum likelihood, clustering
Geophysics
##### Identifiers
OAI: oai:DiVA.org:uu-192106DiVA: diva2:588925
Geophysics
##### Educational program
Master Programme in Physics
##### Presentation
2012-12-19, Dk235, Geocentrum, Villav. 16, 752 36, Uppsala, 16:00 (English)
##### Uppsok
Physics, Chemistry, Mathematics
##### Note

Available from: 2013-01-16 Created: 2013-01-16 Last updated: 2013-01-16Bibliographically approved

#### Open Access in DiVA

fulltext(50380 kB)145 downloads
##### File information
File name FULLTEXT01.pdfFile size 50380 kBChecksum SHA-512
41f2e258edf17374dd51d14fb9c255f07c14a81b85addf693f3b1ac3b906de2601ae8a1cf196693c28f71b15435f72bc076a82e8aaa5ad219dc2596c00933efc
Type fulltextMimetype application/pdf

Li, Ka Lok
Geophysics
Geophysics

#### Search outside of DiVA

GoogleGoogle Scholar
Total: 145 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available
urn-nbn

#### Altmetric score

urn-nbn
Total: 544 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
• apa
• ieee
• modern-language-association-8th-edition
• vancouver
• Other style
More styles
Language
• de-DE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• sv-SE
• Other locale
More languages
Output format
• html
• text
• asciidoc
• rtf
v. 2.29.1
|