The ~M6.8 1868 Hayward earthquake - 140 years later Tom Brocher and colleages U.S. Geological Survey...

The ~M6.8 1868 Hayward earthquake -

140 years later

Tom Brocher and colleages

U.S. Geological Survey

Menlo Park, CA

USGS Fact Sheet 2008-3019

Boatwright & Bundock, USGS OFR 2008-1121

Lawson Report, 1908

1868 “the great 1868 “the great San Francisco San Francisco earthquake”earthquake”

The East Bay north The East Bay north of Oakland was of Oakland was very sparsely very sparsely settled, and few settled, and few reports of the reports of the earthquake are earthquake are available. This available. This region still region still consisted of large consisted of large rancheros and rancheros and cowboys.cowboys.

Boatwright & Bundock, USGS OFR 2008-1121

1868 “the great 1868 “the great San Francisco San Francisco earthquake”earthquake”

Found new reports Found new reports to supplement to supplement Toppozada’s workToppozada’s work

Shaking intensities Shaking intensities were strong from were strong from San Leandro south San Leandro south through Hayward through Hayward towards Fremonttowards Fremont

They were weaker They were weaker in Oakland andin Oakland andMission San JoseMission San Jose

Boatwright & Bundock, USGS OFR 2008-1121

Yu and Segall, JGR, 1996, used historical triangulation survey data to estimate1.9 m of co-seismic slip during the 1868 quake. Creep on the Hayward Fault, afterslip, and slip from other contemporary earthquakes make this a challenging problem.

~M6.8 Oct. 21, 1868 Hayward earthquake

• 30 fatalities, 5 in San Francisco (7th most lethal California earthquake)

• $350,000 (in 1868 dollars) in damage in San Francisco alone

• Extensive damage in San Leandro, Hayward, and Fremont (total population less than 2000)

• Bay Area population was 260,000 (at 7 million, it is now 27 times larger)

USGS Fact Sheet 2008-3019

Impacts of the 1868Hayward earthquake

2nd Alameda Co. Courthouse, San Leandro

Society of California Pioneers

Courthouse

“At San Leandro the shock was more sensibly felt than at any other point on that side of the Bay. All the buildings were terribly shaken, adobes were thrown to the ground, brick structures, and even frame buildings were demolished. The Court House and County Jail were shaken down.”

San Francisco Morning Call, 22 Oct. 1868

Haywards Hotel, Haywards, 1860s

Society of California Pioneers

Hotel

Hayward was heavily damaged by the 1868 earthquake. “Practically not a house was left on its foundations…” “Many buildings were much damaged.” (Lawson Report, 1908).

Mission San Jose

Library of Congress

Bancroft Library

Before

After“The old Mission church, which was of adobe, was shaken down, as were several other buildings at the same place.”

Lawson Report, 1908

Fremont

UC Berkeley, South Hall, built 1873

Stephen Tobriner, Bracing For Disaster, 2006.

The 1868 quake impacted building design in the Bay Area through 1906

Residents noted the localization of damage to areas of made ground (landfill)

Bancroft Library

Reinstein Clothing Factory, 314 California St.

Settlement

Alameda

Oakland

Berkeley

San Leandro

1868 “the great 1868 “the great San Francisco San Francisco earthquake”earthquake”

Despite the Despite the admonition to not admonition to not build on landfill, the build on landfill, the East Bay has East Bay has added a substantial added a substantial amount of landfill amount of landfill since 1868 and since 1868 and 1906.1906.

Boatwright & Bundock, USGS OFR 2008-1121

Alameda

Oakland

Berkeley

San Leandro

1868 “the great 1868 “the great San Francisco San Francisco earthquake”earthquake”

Much of Alameda, Much of Alameda, the Oakland Airport, the Oakland Airport, the Port of Oakland, the Port of Oakland, and Emeryville are and Emeryville are built on landfill.built on landfill.

The liquefaction The liquefaction potential of this potential of this area was recently area was recently studied by Holzer et studied by Holzer et al.al.

Emeryville

Boatwright & Bundock, USGS OFR 2008-1121

X

Phil Stoffer, A Green Guide to the Hayward Fault, 3dparks.wr.usgs.gov/haywardfault

An Ominous Comparison

1868 Hayward Earthquake Commemoration

Help commemorate the 140th anniversary of the 1868 Hayward quake at 7:55 AM Tues. Oct. 21st in a brief public ceremony at the front steps of Mission San Jose, 43300 Mission Blvd., Fremont.

Mission San Jose

1868alliance.org

Abstracts are due by August

15th

see

www.consrv.ca.gov/cgs/news/

eastbayconference.htm

1868alliance.org