Earthquake risk in the United States

1952 ◽  
Vol 42 (1) ◽  
pp. 110-110
Keyword(s):  
United States ◽  
The United States ◽  
Earthquake Risk

scholarly journals Earthquake Early Warning ShakeAlert 2.0: Public Rollout

2020 ◽  
Vol 91 (3) ◽  
pp. 1763-1775 ◽  
Author(s):  
Monica D. Kohler ◽  
Deborah E. Smith ◽  
Jennifer Andrews ◽  
Angela I. Chung ◽  
Renate Hartog ◽  
...  
Keyword(s):  
United States ◽  
Early Warning ◽  
Performance Metrics ◽  
Warning System ◽  
The United States ◽  
Earthquake Early Warning ◽  
Earthquake Risk ◽  
Waveform Data ◽  
Ground Shaking ◽  
Event Rates

Abstract The ShakeAlert earthquake early warning system is designed to automatically identify and characterize the initiation and rupture evolution of large earthquakes, estimate the intensity of ground shaking that will result, and deliver alerts to people and systems that may experience shaking, prior to the occurrence of shaking at their location. It is configured to issue alerts to locations within the West Coast of the United States. In 2018, ShakeAlert 2.0 went live in a regional public test in the first phase of a general public rollout. The ShakeAlert system is now providing alerts to more than 60 institutional partners in the three states of the western United States where most of the nation’s earthquake risk is concentrated: California, Oregon, and Washington. The ShakeAlert 2.0 product for public alerting is a message containing a polygon enclosing a region predicted to experience modified Mercalli intensity (MMI) threshold levels that depend on the delivery method. Wireless Emergency Alerts are delivered for M 5+ earthquakes with expected shaking of MMI≥IV. For cell phone apps, the thresholds are M 4.5+ and MMI≥III. A polygon format alert is the easiest description for selective rebroadcasting mechanisms (e.g., cell towers) and is a requirement for some mass notification systems such as the Federal Emergency Management Agency’s Integrated Public Alert and Warning System. ShakeAlert 2.0 was tested using historic waveform data consisting of 60 M 3.5+ and 25 M 5.0+ earthquakes, in addition to other anomalous waveforms such as calibration signals. For the historic event test, the average M 5+ false alert and missed event rates for ShakeAlert 2.0 are 8% and 16%. The M 3.5+ false alert and missed event rates are 10% and 36.7%. Real-time performance metrics are also presented to assess how the system behaves in regions that are well-instrumented, sparsely instrumented, and for offshore earthquakes.

scholarly journals Seismic regionalization

1959 ◽  
Vol 49 (2) ◽  
pp. 123-162
Author(s):  
C. F. Richter
Keyword(s):  
United States ◽  
Los Angeles ◽  
Large Scale ◽  
Active Faults ◽  
Local Variation ◽  
The United States ◽  
Earthquake Risk ◽  
Small Scale ◽  
Los Angeles Basin ◽  
Mountain Areas

abstract In the USSR earthquake risk is now officially mapped by division into areas numbered with the degrees of the Modified Mercalli intensity scale, to show maximum reasonably expectable intensity during future earthquakes on ground of the prevailing character. This paper presents and discusses maps on the same plan for the Los Angeles Basin and its vicinity, for California, and for the United States. The effect of variation of ground from point to point can be shown only on a large scale. This is microregionalization; the map for the Los Angeles Basin is an example. Small-scale regionalization maps require generalization. Prevailing ground is selected, not strictly by percentage of area, but by considering the foundation likely to be used for construction, in mountainous areas mostly small alluvial patches less stable than the surrounding rock. Regionalization and especially microregionalization can be used in construction and planning, as indicating maximum effects to be considered in designing permanent structures. In adjusting insurance rates, and in designing temporary structures, statistical frequency of occurrence is also involved. Over small areas, regionalization depends largely on local variation of ground and geology; over large areas, distance from active faults must be considered. Attention should be given to the effect of structural trends and of wave path on the form of isoseismal curves. Mapping for the Los Angeles Basin area is reasonably definite. That for California is fairly reliable, but less so in desert and mountain areas. That for the United States is in part highly speculative and subject to substantial change.

Earthquake Risk and Hazard Mitigation in Turkey

2002 ◽  
Vol 18 (3) ◽  
pp. 427-447 ◽  
Author(s):  
Pelin G. Bakır ◽  
Hasan M. Bodurog˘lu
Keyword(s):  
United States ◽  
Disaster Management ◽  
Management System ◽  
Management Practices ◽  
Hazard Mitigation ◽  
The United States ◽  
Professional Standards ◽  
Earthquake Risk ◽  
Environmental Consequences ◽  
Disaster Management System

The last two earthquakes in Marmara have been catastrophic disasters beyond all limits of perception. On 17 August 1999, there were 1 million people trapped under debris, eighteen thousand people had lost their lives, and hundreds of thousands had been evacuated from their homes. Roads had buckled and bridges had fallen down. On 12 November 1999 another earthquake hit Düzce. This earthquake also caused high casualties. There were 894 deaths and 4,948 injuries. Both of the disasters had social, technical, administrative, legal, economical as well as environmental consequences. This paper presents a brief overview of these earthquakes in terms of the six aspects mentioned above. Disaster management practices are also investigated. The authors are of the opinion that it is not only the buildings but also poor disaster management before, during, and after the disaster that kill people in severe earthquakes. The present disaster management system of Turkey is compared against professional standards of the United States and Japan. The authors systematically document where performance failed and offer proposals for change within the Turkish disaster management system.

scholarly journals Refurbishing earthquake risk buildings in U.S.A.

1981 ◽  
Vol 14 (2) ◽  
pp. 43-53
Author(s):  
D. B. Leadbeater
Keyword(s):  
United States ◽  
New Zealand ◽  
Los Angeles ◽  
San Francisco ◽  
Systematic Approach ◽  
The United States ◽  
Earthquake Risk ◽  
Long Beach ◽  
Testing Procedures

The paper reviews current ordinances and standards in use and under discussion on the western seaboard of the United States with particular reference to the cities of Seattle, Sacramento, Santa Rosa, Long Beach, Los Angeles and San Francisco. Details of various upgrading methods and testing procedures are included. In New Zealand, both the objective and standards required to achieve that objective appear far more clear. Some personal thoughts are given on a more systematic approach to the upgrading of high earthquake risk buildings in this country.

A Consistent Cross-Border Seismic Hazard Methodology for Loss Estimation and Risk Management along the Border Regions of Canada and the United States

2015 ◽  
Vol 31 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Paul C. Thenhaus ◽  
Kenneth W. Campbell ◽  
Nitin Gupta ◽  
David F. Smith ◽  
Mahmoud M. Khater
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
The United States ◽  
Cascadia Subduction Zone ◽  
Earthquake Risk ◽  
Site Conditions ◽  
Site Factors ◽  
Local Site ◽  
Spatially Varying ◽  
Risk Managers

We provide a methodology that seamlessly integrates national seismic hazard models across the Canada-U.S. border to provide earthquake risk managers with updated and consistent seismic hazard science and technology in the two countries. Consistent with our U.S. hazard model, we developed a new Canadian model that incorporates (1) spatially varying seismicity for the major metropolitan areas of southeastern and southwestern Canada and the United States, (2) a comprehensive probabilistic model for the Cascadia subduction zone that includes M 8.0–9.2 interface earthquakes, (3) a consistent set of ground motion prediction equations across eastern and western North America, and (4) a soil-based attenuation (SBA) methodology that mitigates uncertainty in the conversion of earthquake motions from rock to soil, on which the majority of exposure is located. NEHRP site conditions are mapped for all of Canada from existing geological data, and NEHRP site factors are used to account for local site conditions.

Sign in / Sign up

Export Citation Format

Share Document