APPLICATION OF THE THEORY OF REGIONALIZED VARIABLES TO EARTHQUAKE PARAMETRIC ESTIMATION AND SIMULATION (CALIFORNIA).
AuthorCARR, JAMES RUSSELL.
KeywordsEarthquakes -- Data processing.
Earthquake prediction -- Data processing.
Earthquakes -- Mathematical models.
Earthquake prediction -- Mathematical models.
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PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractHistorical accounts of earthquakes show a high degree of spatial variability and uncertainty associated with ground motion. For this reason, historical data are not often used as input for earthquake hazard assessment. Regionally, however, earthquake ground motion is related by the concept of attenuation. Seismic hazard assessment techniques usually rely on catalogues of earthquake epicenters together with empirical attenuation relationships to define the seismic hazard for a particular region. Such techniques, however, overlook local variations in ground motion associated with actual earthquakes. A technique for seismic hazard assessment that includes historical data using the theory of regionalized variables and linear estimation techniques best represents ground motion dichotomy. Modified Mercalli intensity observations for the period 1930 through 1971 were treated as regionalized variables to define the seismic hazard for a region of Southern California centered around San Fernando. Despite variations in construction quality and individual sensitivity to ground motion, intensity values associated with seventy percent of the earthquakes that occurred during this period, for which at least five intensity observations were recorded, were accurately treated as regionalized variables. A Gumbel analysis computed using spatially regular data sets developed from these intensity values precisely associated high hazard regions with active faults near San Fernando. Other earthquake ground motion data can also be treated, accurately, as regionalized variables. These data include peak instrument recordings of spectral acceleration, velocity, and displacement. Moreover, response to earthquake ground motion at discrete frequencies, as recorded by response spectra, is also regionalized. These data, therefore, are accurately estimated using kriging. Fundamentally, because earthquake ground motion is shown to be a regionalized variable, all aspects of regionalized variables theory are applicable for these data, including disjunctive kriging, conditional simulation, and co-kriging.
Degree ProgramMining and Geological Engineering
Degree GrantorUniversity of Arizona
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COMPLEX RUPTURE PROCESSES OF THE SOLOMON ISLANDS SUBDUCTION ZONE EARTHQUAKE AND SUBDUCTION CONTROLLED UPPER MANTLE STRUCTURE BENEATH ANATOLIABiryol, Cemal Berk; Beck, Susan L.; Zandt, George; Johnson, Roy A.; Bennett, Richard A.; Kapp, Paul (The University of Arizona., 2009)This dissertation explores subduction zone-related deformation both on short time scales in the form of subduction zone earthquakes and over larger time and geographical scales in the form of subduction rollback or detachment of the subducting lithosphere. The study presented here is composed of two parts. First, we analyzed the source-rupture processes of the April 1, 2007 Solomon Islands Earthquake (Mw=8.1) using a body-wave inversion technique. Our analysis indicated that the earthquake ruptured approximately 240 km of the southeast Pacific subduction zone in two sub-events.In the second part of this study, we used shear-wave splitting analysis to investigate the effects of the subducting African lithosphere on the upper-mantle flow field beneath the Anatolian Plate in the Eastern Mediterranean region. Our shear-wave splitting results are consistent with relatively uniform southwest-directed flow towards the actively southwestward-retreating Aegean slab. Based on spatial variations in observed delay times we identified varying flow speeds beneath Anatolia and we attribute this variation to the differential retreat rates of the Aegean and the Cyprean trenches.Finally, we used teleseismic P-wave travel-time tomography to image the geometry of the subducting African lithosphere beneath the Anatolia region. Our tomograms show that the subducting African lithosphere is partitioned into at least two segments along the Cyprean and the Aegean trenches. We observed a gap between the two segments through which hot asthenosphere ascends beneath the volcanic fields of western Anatolia. Our results show that the Cyprean slab is steeper than the Aegean slab. We inferred that this steep geometry, in part, controls the flow regime of asthenosphere beneath Anatolia causing variations in flow speeds inferred from shear-wave splitting analysis.
IMPLICATIONS FOR MODELS OF FAULT BEHAVIOR FROM EARTHQUAKE SURFACE-DISPLACEMENT ALONG ADJACENT SEGMENTS OF THE LOST RIVER FAULT, IDAHOBull, William B.; Vincent, Kirk Robert; Bull, William B.; Baker, Victor R.; Chase, Clement G.; Hendricks, David M.; Wallace, Terry C. (The University of Arizona., 1995)This research evaluates models of earthquake behavior and fault segmentation, by quantifying the rupture-magnitude pattern along the trace of coseismic surface rupture for each of four earthquakes. One is the 1983 (Ms = 7.3) Borah Peak, Idaho, earthquake and three are prehistoric. Two earthquakes occurred along each of the adjacent Thousand Springs and Mackay Segments (TSS and MS) of the Lost River fault in east-central Idaho, and within their intervening segment boundary. The apparent vertical slip-component (throw) was measured as the vertical separation of surveyed longitudinal profiles of faulted stream floodplains, terraces, and alluvial fans, and relative uncertainty in the measurements was obtained. The true vertical slip-component (VD) was calculated to account for geometric distortion in throw data. Knowledge of fault dip is required, and was estimated using structural contour models of the fault. The preferred model relies on the measured orientation of the 1983 net-slip vector at a faulted-fence site, but the calculation is more dependent on profile gradient then on fault dip. The ages of faulted landforms are constrained by a dated soil chronosequence (in calibrated calendar years BP). The period of record is approximately ≈ 17 ky, the age of ubiquitous late-glacial fans. The Borah Peak surface rupture is 5 km longer than previously thought. 1983 rupture VD was uniformly approximately ≈ 2 m along the southeastern half of the TSS and penetrated the segment boundary with uniform VD of 0.5 m. The penultimate earthquake on the TSS occurred between 10 and 11 ka, and had rupture magnitude and location nearly identical to the 1983 earthquake. On the Mackay Segment (MS), an earthquake occurred at approximately ≈ 5 ka with ruptures penetrating the segment boundary. Apparently a previous event occurred between 12 and 17 ka. The cumulative VD for the period of record is uniform 4 to 4.5 m on both the TSS and the MS, but only 2 m ofVD in the segment boundary. There is no evidence for medium sized earthquakes. All the evidence can be explained by four nearly identical, large magnitude characteristic earthquakes on a segmented fault.