About 25 percent of the 2,500 earthquakes reported from 1638-1928 and 10 percent of the 18,500 events from 1928-80 do not have instrumental epicenters; this omission is mainly due to the fact that...Several of the reporting cities (or localities) listed in the file have not been assigned geographic coordinates.The file contains data primarily for those earthquakes that have epicenters in the United States, nearby U.S. territories, and areas of Canada and Mexico that border the United States. Data for a f...
- Description of Database
- Definition of Variables
- Collecting Data on Earthquake Intensity
Year Mo Da Hr Mn Sec
1. The Date and Time are listed in Universal Coordinated Time and are Year, Month (Mo), Day (Da), Hour (Hr), Minute (Mn), Second (Sec)
1. Number of hours to subtract from the Date and Time given in Universal Coordinated Time to get local standard time for the epicenter. In general:
1. Unpublished or grouped intensity 2. U = Intensity (MMI) assigned that was not listed in the source document. 3. G = Intensity grouped I-III in the source document was reassigned intensity III.
The U.S. Geological Survey (USGS) is the Federal agency responsible for collecting earthquake intensity data. The USGS carries out this responsibility using a questionnaire called "Earthquake Report," and also sends field investigators to the scene of destructive earthquakes to analyze the resulting damage. Different versions of the questionnaire have been used since the mid-1920s by several groups who were responsible for collecting intensity data. The present questionnaire contains pertinent questions about earthquake effects that enable a seismologist to evaluate the intensity of the earthquake in all parts of the shaken area; it also is designed specifically for computer processing. In the past, the USGS sent questionnaires immediately after each U.S. earthquake to postmasters, National Weather Service offices, military installations, and others, requesting that they report all effects of the earthquake in their area. If the earthquake was damaging, expert observers travelled to...
The main sources of data used in compiling the Earthquake Intensity Database Earthquake History of the United States This publication is a summary of all earthquakes (intensity V and above) that have occurred in the United States and its territories from earliest recorded history (about 1638 in the New England region) through 1980. The 1982 edition of this publication (Coffman and others, 1982) contains revised epicenters and intensities for several earthquakes. This source, therefore, is the authority for epicenters of significant earthquakes in the file and also for most intensities of MM intensity >= V. In addition, pages xi-xii of "Earthquake History" contain several addenda and corrigenda, which have been used to update information in the Intensity File. United States Earthquakes Much of the intensity data in the Earthquake Intensity Database for 1928-85 were taken from this annual report. Its publication in 1928 began a continuing program of collecting comprehensive effect rep...
damage-intensity relation is very important to be used for predicting the damage level due a specified to earthquake. The damage level is needed by The Government to develop an emergency and reconstruction budget plan for earthquake disaster in future. SUMMARY: Keywords: Earthquake, damage assessment, earthquake intensity. 1. INTRODUCTION . On ...
People also ask
Which is the best measure of earthquake intensity?
How are magnitude, energy release, and shaking intensity related?
How is the magnitude of an earthquake in California determined?
How is the energy release of an earthquake calculated?
- Magnitude. Sketch of a traditional seismometer. (Public domain.) The time, location, and magnitude of an earthquake can be determined from the data recorded by seismometer.
- Energy Release. Earthquake magnitudes and energy release, and comparison with other natural and man-made events. (Courtesy Incorporated Research Institutes for Seismology, IRIS.)
- Intensity. Did You Feel It? map for the M6.0 Napa, California earthquake on August 24, 2014. The earthquake epicenter is shown as a star, and the geocoded intensities are shown as small colored squares.
- Examples. These examples illustrate how locations (and depth), magnitudes, intensity, and faults (and rupture) characteristics are dependent and related.
In hazard analysis, intensity measures (IM) and their annual frequency of exceedance (λIM) are defined by probabilistic seismic hazard assessment (PSHA).
- Subash Ghimire, Philippe Guéguen, Ariana Astorga
damage assessment and seismic intensity analysis s153 The building stock in the region can be grouped, according to ability to resist damage from earthquakes, into four vulnerability classes ...
Jan 01, 2020 · Seismic design practices and seismic response analyses of civil structures and nuclear power plants (NPPs) have conventionally used the peak ground acceleration (PGA) or spectral acceleration (Sa) as an intensity measure (IM) of an earthquake. However, there are many other earthquake IMs that were proposed by various researchers.
- Duy Duan Nguyen, Duy Duan Nguyen, Bidhek Thusa, Tong Seok Han, Tae Hyung Lee
Jun 01, 2012 · The intensity values in 111 cities in the earthquake's damage area are estimated from the field surveys considering the distribution of the observed damage in adobe and masonry single-family buildings of one and two stories.
- Maximiliano Astroza, Sergio Ruiz, Sergio Ruiz, Rodrigo Astroza, Rodrigo Astroza
Feb 15, 2018 · The workflow is: Use Living Atlas to create a recent earthquake map. Identify a quake event for the analysis. Filter the intensity layer to use only areas where the intensity is 4 or greater.
- Bern Szukalski
It is composed of 12 increasing levels of intensity which range from ground shaking to catastrophic destruction. The lower levels of the intensity scale indicate the effect of earthquake felt by people, and the higher levels indicate the observed structural damage. Table 1 describes the 12 levels of Modified Mercalli Intensity Scale.