Author: John N. Baldwin
Publisher:
ISBN:
Category : Earthquakes
Languages : en
Pages : 254
Book Description
Paleoseismic Investigation of the San Andreas Fault on the North Coast Segment, Near Manchester, California
Paleoseismic Investigations of the Northern San Andreas Fault at the Vedanta Site, Marin County, California
Author: Nelson Timothy Hall
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 144
Book Description
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 144
Book Description
Paleoseismic Investigations of the San Andreas Fault on the San Francisco Peninsula, California: Text and figures
Author: Nelson Timothy Hall
Publisher:
ISBN:
Category : Earthquake hazard analysis
Languages : en
Pages : 178
Book Description
Publisher:
ISBN:
Category : Earthquake hazard analysis
Languages : en
Pages : 178
Book Description
Paleoseismic Studies of the Northern San Andreas Fault at Vedanta Marsh Site, Olema, California
Author: Hongwei Zhang
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 686
Book Description
The northern San Andreas fault (SAF) ruptured in 1906 and generated the Great San Francisco Earthquake. This study involves collection and interpretation of paleoseismic data from the North Coast segment of the norther SAF at Vedanta marsh, Olema, California, to determine the timing of prehistoric large earthquakes, coseismic slips, and earthquake recurrence on this fault segment. These important parameters will test the existing earthquake models and add new data to the San Francisco Bay Area earthquake probability analysis. Late Holocene sediments deposited at Vedanta marsh preserve a continuous record of prehistoric earthquakes. Excavations into the marsh provided exposure of the sediments across the SAF zone. Well-defined marsh stratigraphy and abundant in situ organic material allow the determination of the first long, high-resolution, event-by-event record of earthquakes for the northern SAF. Evidence for twelve earthquakes, including the 1906 earthquake, have been identified from the main fault zone based on fault outward splays, fault upward termination, fissures, colluvial wedges, and soft-sediment deformation. All of these features occurred since the deposition of a unit that is approximately 3000 years old. The age of eleven pre-1906 seismic events are well bracketed by radiocarbon dates and age modeling using the OxCal radiocarbon analysis program. The average recurrence interval at the Vedanta site is ~ 250 years. However, individual recurrence intervals are quite irregular, ranging from as short as 53 years to as long as 605 years. From comparisons with other sites on the northern SAF, I interpret four pre-1906 events may have ruptured the entire North Coast segment, including earthquakes in the following ranges: AD 1670 - 1740; AD 1290 - 1380; AD 1100 - 1165; and AD 650 -710. A buried paleochannel had been right-laterally offset 7.8 - 8.3 m by coseismic slip of the 1906 and the penultimate earthquakes. Historical record of the 1906 coseismic slip measured near the excavation site was ~ 5 m. If we assume 5 m of 1906 slip at the marsh site, then the coseismic slip of the penultimate event is between 2.8 - 3.3 m. Timing (AD 1670 - 1740) and coseismic slip of the penultimate event indicate that the northern SAF may rupture in sequences of closely timed earthquakes on shorter segments, and does not support the assumption that the fault has failed as a single, long rupture similar to 1906 in mid 1600s.
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 686
Book Description
The northern San Andreas fault (SAF) ruptured in 1906 and generated the Great San Francisco Earthquake. This study involves collection and interpretation of paleoseismic data from the North Coast segment of the norther SAF at Vedanta marsh, Olema, California, to determine the timing of prehistoric large earthquakes, coseismic slips, and earthquake recurrence on this fault segment. These important parameters will test the existing earthquake models and add new data to the San Francisco Bay Area earthquake probability analysis. Late Holocene sediments deposited at Vedanta marsh preserve a continuous record of prehistoric earthquakes. Excavations into the marsh provided exposure of the sediments across the SAF zone. Well-defined marsh stratigraphy and abundant in situ organic material allow the determination of the first long, high-resolution, event-by-event record of earthquakes for the northern SAF. Evidence for twelve earthquakes, including the 1906 earthquake, have been identified from the main fault zone based on fault outward splays, fault upward termination, fissures, colluvial wedges, and soft-sediment deformation. All of these features occurred since the deposition of a unit that is approximately 3000 years old. The age of eleven pre-1906 seismic events are well bracketed by radiocarbon dates and age modeling using the OxCal radiocarbon analysis program. The average recurrence interval at the Vedanta site is ~ 250 years. However, individual recurrence intervals are quite irregular, ranging from as short as 53 years to as long as 605 years. From comparisons with other sites on the northern SAF, I interpret four pre-1906 events may have ruptured the entire North Coast segment, including earthquakes in the following ranges: AD 1670 - 1740; AD 1290 - 1380; AD 1100 - 1165; and AD 650 -710. A buried paleochannel had been right-laterally offset 7.8 - 8.3 m by coseismic slip of the 1906 and the penultimate earthquakes. Historical record of the 1906 coseismic slip measured near the excavation site was ~ 5 m. If we assume 5 m of 1906 slip at the marsh site, then the coseismic slip of the penultimate event is between 2.8 - 3.3 m. Timing (AD 1670 - 1740) and coseismic slip of the penultimate event indicate that the northern SAF may rupture in sequences of closely timed earthquakes on shorter segments, and does not support the assumption that the fault has failed as a single, long rupture similar to 1906 in mid 1600s.
Paleoseismic and Geoarchaeologic Investigations of the Northern San Andreas Fault, Fort Ross State Historic Park, California
Author:
Publisher:
ISBN:
Category : Archaeological geology
Languages : en
Pages : 42
Book Description
Publisher:
ISBN:
Category : Archaeological geology
Languages : en
Pages : 42
Book Description
Paleoseismic Investigations of the San Bernardino Segment of the San Andreas Fault at Plunge Creek, San Bernardino, California
Author: Safaa Abdul Dergham
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 96
Book Description
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 96
Book Description
Paleoseismic and Archaeologic Investigation of the Northern San Gregorio Fault, Seal Cove, San Mateo County, California
Paleoseismic Recurrence Investigation of the Santa Cruz Mountains Segment of the San Andreas Fault Near Watsonville, California
Author: Gordon Frank Heingartner
Publisher:
ISBN:
Category : Earthquakes
Languages : en
Pages : 272
Book Description
Publisher:
ISBN:
Category : Earthquakes
Languages : en
Pages : 272
Book Description
Paleoseismic Investigation of the San Andreas Fault Zone in Portola Valley, California
Author: Robert Harvey Wright
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 82
Book Description
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 82
Book Description
National Earthquake Hazards Reduction Program, Annual Project Summaries, XXXVI
Author:
Publisher:
ISBN:
Category : Earthquake hazard analysis
Languages : en
Pages : 564
Book Description
Publisher:
ISBN:
Category : Earthquake hazard analysis
Languages : en
Pages : 564
Book Description