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Date Permissions Signed

7-2015

Date of Award

Summer 2015

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Geology

First Advisor

Amos, Colin B.

Second Advisor

Schermer, Elizabeth, 1959-

Third Advisor

Clark, Douglas H., 1961-

Abstract

The 1872 Owens Valley earthquake ranks among the largest historical earthquakes in California. Relatively sparse field data and a complex rupture trace inhibited attempts to define the slip distribution and reconcile the total moment release. We present a new, comprehensive surface-slip record based on lidar and field investigation, documenting 183 measurements of laterally and vertically displaced landforms for 1872 and earlier Owens Valley fault earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sub-linear topographic features. This MATLAB-based GUI, OffsetXcor, produces a uniquely-shaped probability density function (PDF) of fault slip for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common offset values corresponding to single- and multiple-event displacements. Dextral offsets for 1872 vary systematically from ~1.0 – 6.0 m and average 3.3 ± 1.2 m (2). The corresponding vertical shift is between ~0.1 to 2.4 m and predominantly east-side down, with a mean of 0.8 ± 0.5 m (2). The horizontal-to-vertical ratio averaged at specific sites is ~6:1, similar to previously reported values. We attribute progressively higher-offset lateral COPD peaks at 7.4 ± 1.3 m, 12.4 ± 1.2 m, and 16.6 ± 1.4 m (2) to three earlier surface ruptures. COPD peaks are relatively complex and bimodal, reflecting heterogeneous slip along geometric segments and subordinate strands. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively constant, modest rates of fault slip, averaging between ~0.6-1.6 mm/yr (1) over the Mid-to-Late Quaternary.

Type

Text

DOI

https://doi.org/10.25710/5wy5-8151

Publisher

Western Washington University

OCLC Number

915591425

Subject – LCSH

Surface fault ruptures--California--Owens Valley

Geographic Coverage

Owens Valley (Calif.)

Format

application/pdf

Genre/Form

masters theses

Language

English

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Table_S1.pdf (52 kB)
Table_S2.csv (24 kB)
Table_S3.csv (6 kB)
Data_Set_S1.zip (566 kB)
Data_Set_S2.zip (21 kB)
Data_Set_S3.zip (255 kB)
Data_Set_S4.zip (822348 kB)
Software_S1.zip (64 kB)

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