Historical Earthquakes, Magnitude 5.5+, 1600 to present

FGDC Metadata:

Identification Information:

Citation:

Citation Information:

Publication Date: 20200618

Title: Historical Earthquakes, Magnitude 5.5+, 1600 to present

Geospatial Data Presentation Form: vector digital data

Description:

Abstract: Earthquakes extracted from the USGS Earthquake Catalog and converted to an ESRI feature class using Python.Original values are left intact with the exception of conversion of the elevation component of the coordinate to a negative value in KM and the conversion of null elevation values to 0, and the conversion of null values for "mag", "mmi", "nst", "gap", and "dmin" to -1.0 for insertion to a database table.

Purpose: A dataset with earthquakes M2.5+ from 1600 to present filtered to show M5.5+. These data are extracted from the USGS's data feeds and updated daily.

Status:

Progress: In work

Maintenance and Update Frequency: Unknown

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -128.000000

East Bounding Coordinate: -110.000000

North Bounding Coordinate: 49.996000

South Bounding Coordinate: 24.607000

Keywords:

Theme:

Theme Keyword Thesaurus: None

Theme Keyword: California

Theme Keyword: Western Continental US

Theme Keyword: Magnitude 2.5 Plus

Theme Keyword: California Geological Survey

Theme Keyword: USGS

Theme Keyword: Earthquakes

Theme:

Theme Keyword Thesaurus: ISO 19115 Topic Categories

Theme Keyword: geoscientificInformation

Place:

Place Keyword Thesaurus: None

Place Keyword: California,

Place Keyword: Western Continental United States

Access Constraints: None

Use Constraints: The Department of Conservation (DOC) and its divisions provide data for informational purposes, including data from third parties. Data is expected to be reliable. However, no warranty, expressed or implied, is made by DOC regarding: accuracy, adequacy, completeness, legality, reliability, merchantability, fitness for a particular purpose,freedom from contamination by computer viruses, or usefulness of any information. All warranties of any kind, express or implied, including, but not limited to, the implied warranties of non-infringement of proprietary rights ARE DISCLAIMED.Data provided through this website, unless statutorily required, may be updated, amended, or deleted at any time and without notice. The location of items may change as menus, homepages, and files are reorganized. DOC does not warrant that this service will be uninterrupted or error free.The use of services or the downloading of information is done at your own discretion and risk. This disclaimer of liability applies to all claims for damages or injury, including, but not limited to: failure of performance, error, omission, interruption, deletion, defect, delay in operation or transmission, computer virus, or unauthorized access to or alteration of data, whether for breach of contract, tortuous behavior, negligence, or under any other cause of action.Before accessing data and using the services provided, review DOC’s Conditions of Use, Privacy Policy, and Disclaimer and Copyright, and which are incorporated by reference into this Disclaimer.

Data Set Credit: United States Geological Survey, California Department of Conservation, and contributing organizations

Native Data Set Environment: Esri ArcGIS 12.4.2.19948

Data Quality Information:

Lineage:

Source Information:

Type of Source Media: None

Source Contribution: https://earthquake.usgs.gov/earthquakes/search/

Spatial Data Organization Information:

Direct Spatial Reference Method: Vector

Point and Vector Object Information:

SDTS Terms Description:

SDTS Point and Vector Object Type: Entity point

Point and Vector Object Count: 131487

Entity and Attribute Information:

Detailed Description:

Entity Type:

Entity Type Label: EQ_HistM2p5

Attribute:

Attribute Label: OBJECTID

Attribute Definition: Internal feature number.

Attribute Definition Source: Esri

Attribute Domain Values:

Unrepresentable Domain: Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute Label: net

Attribute Definition: The ID of a data contributor. Identifies the network considered to be the preferred source of information for this event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: ids

Attribute Definition: A comma-separated list of event ids that are associated to an event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: mag

Attribute Definition: The magnitude of the event. The magnitude reported is that which the U.S. Geological Survey considers official for this earthquake, and was the best available estimate of the earthquake’s size, at the time that this page was created. Other magnitudes associated with web pages linked from here are those determined at various times following the earthquake with different types of seismic data. Although they are legitimate estimates of magnitude, the U.S. Geological Survey does not consider them to be the preferred "official" magnitude for the event. Earthquake magnitude is a measure of the size of an earthquake at its source. It is a logarithmic measure. At the same distance from the earthquake, the amplitude of the seismic waves from which the magnitude is determined are approximately 10 times as large during a magnitude 5 earthquake as during a magnitude 4 earthquake. The total amount of energy released by the earthquake usually goes up by a larger factor: for many commonly used magnitude types, the total energy of an average earthquake goes up by a factor of approximately 32 for each unit increase in magnitude. There are various ways that magnitude may be calculated from seismograms. Different methods are effective for different sizes of earthquakes and different distances between the earthquake source and the recording station. The various magnitude types are generally defined so as to yield magnitude values that agree to within a few-tenths of a magnitude-unit for earthquakes in a middle range of recorded-earthquake sizes, but the various magnitude-types may have values that differ by more than a magnitude-unit for very large and very small earthquakes as well as for some specific classes of seismic source. This is because earthquakes are commonly complex events that release energy over a wide range of frequencies and at varying amounts as the faulting or rupture process occurs. The various types of magnitude measure different aspects of the seismic radiation (e.g., low-frequency energy vs. high-frequency energy). The relationship among values of different magnitude types that are assigned to a particular seismic event may enable the seismologist to better understand the processes at the focus of the seismic event. The various magnitude-types are not all available at the same time for a particular earthquake. Preliminary magnitudes based on incomplete but rapidly-available data are sometimes estimated and reported. For example, the Tsunami Warning Centers will calculate a preliminary magnitude and location for an event as soon as sufficient data are available to make an estimate. In this case, time is of the essence in order to broadcast a warning if tsunami waves are likely to be generated by the event. Such preliminary magnitudes are superseded by improved estimates of magnitude as more data become available. For large earthquakes of the present era, the magnitude that is ultimately selected as the preferred magnitude for reporting to the public is commonly a moment magnitude that is based on the scalar seismic-moment of an earthquake determined by calculation of the seismic moment-tensor that best accounts for the character of the seismic waves generated by the earthquake. The scalar seismic-moment, a parameter of the seismic moment-tensor, can also be estimated via the multiplicative product rigidity of faulted rock x area of fault rupture x average fault displacement during the earthquake.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: Shape

Attribute Definition: Feature geometry.

Attribute Definition Source: Esri

Attribute Domain Values:

Unrepresentable Domain: Coordinates defining the features.

Attribute:

Attribute Label: types

Attribute Definition: A comma-separated list of product types associated to this event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: nst

Attribute Definition: The total number of seismic stations used to determine earthquake location. Number of seismic stations which reported P- and S-arrival times for this earthquake. This number may be larger than the Number of Phases Used if arrival times are rejected because the distance to a seismic station exceeds the maximum allowable distance or because the arrival-time observation is inconsistent with the solution.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: sources

Attribute Definition: A comma-separated list of network contributors. https://earthquake.usgs.gov/data/comcat/data-eventterms.php#net

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: depth

Attribute Definition: Depth in km extracted from the geometry object downloaded.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: dtevent

Attribute Definition: Date and time of the event in UTC as converted from the "time" field obtained from the Earthquake Catalog. "Time" description. Time when the event occurred. Times are reported in milliseconds since the epoch ( 1970-01-01T00:00:00.000Z), and do not include leap seconds. In certain output formats, the date is formatted for readability. We indicate the date and time when the earthquake initiates rupture, which is known as the "origin" time. Note that large earthquakes can continue rupturing for many 10's of seconds. We provide time in UTC (Coordinated Universal Time). Seismologists use UTC to avoid confusion caused by local time zones and daylight savings time. On the individual event pages, times are also provided for the time at the epicenter, and your local time based on the time your computer is set.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: title

Attribute Definition: title of the earthquake including magnitude and place description.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: sig

Attribute Definition: A number describing how significant the event is. Larger numbers indicate a more significant event. This value is determined on a number of factors, including: magnitude, maximum MMI, felt reports, and estimated impact.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: alert

Attribute Definition: The alert level from the PAGER earthquake impact scale.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: status

Attribute Definition: Indicates whether the event has been reviewed by a human. Status is either automatic or reviewed. Automatic events are directly posted by automatic processing systems and have not been verified or altered by a human. Reviewed events have been looked at by a human. The level of review can range from a quick validity check to a careful reanalysis of the event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: cdi

Attribute Definition: The maximum reported intensity for the event. Computed by DYFI. While typically reported as a roman numeral, for the purposes of this API, intensity is expected as the decimal equivalent of the roman numeral. Learn more about magnitude vs. intensity.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: mmi

Attribute Definition: The maximum estimated instrumental intensity for the event. Computed by ShakeMap. While typically reported as a roman numeral, for the purposes of this API, intensity is expected as the decimal equivalent of the roman numeral. Learn more about magnitude vs. intensity.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: detail

Attribute Definition: Link to GeoJSON detail feed from a GeoJSON summary feed. NOTE: When searching and using geojson with callback, no callback is included in the detail url.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: felt

Attribute Definition: The total number of felt reports submitted to the DYFI? system.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: dmin

Attribute Definition: Horizontal distance from the epicenter to the nearest station (in degrees). 1 degree is approximately 111.2 kilometers. In general, the smaller this number, the more reliable is the calculated depth of the earthquake.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: code

Attribute Definition: An identifying code assigned by - and unique from - the corresponding source for the event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: dtupdated

Attribute Definition: Time when the event was most recently updated. Times are reported in milliseconds since the epoch. In certain output formats, the date is formatted for readability.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: type

Attribute Definition: Type of seismic event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: gap

Attribute Definition: The largest azimuthal gap between azimuthally adjacent stations (in degrees). In general, the smaller this number, the more reliable is the calculated horizontal position of the earthquake. Earthquake locations in which the azimuthal gap exceeds 180 degrees typically have large location and depth uncertainties.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: magType

Attribute Definition: The method or algorithm used to calculate the preferred magnitude for the event. https://www.usgs.gov/natural-hazards/earthquake-hazards/science/magnitude-types

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: url

Attribute Definition: Link to USGS Event Page for event.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: place

Attribute Definition: Textual description of named geographic region near to the event. This may be a city name, or a Flinn-Engdahl Region name. We use a GeoNames dataset to reference populated places that are in close proximity to a seismic event. GeoNames has compiled a list of cities in the United States where the population is 1,000 or greater (cities1000.txt). This is the primary list that we use when selecting nearby places. In order to provide the public with a better understanding for the location of an event we try to list a variety of places in our nearby places list. This includes the closest known populated place in relation to the seismic event (which based on our dataset will have a population of 1,000 or greater). We also include the next 3 closest places that have a population of 10,000 or greater, and finally make sure to include the closest capital city to the seismic event. The reference point for the descriptive locations is usually either the City Hall of the town (or prominent intersection in the middle of town if there is no City Hall), but please refer to the GeoNames website for the most accurate information on their data. If there is no nearby city within 300 kilometers (or if the nearby cities database is unavailable for some reason), the Flinn-Engdahl (F-E) seismic and geographical regionalization scheme is used. The boundaries of these regions are defined at one-degree intervals and therefore differ from irregular political boundaries. For example, F-E region 545 (Northern Italy) also includes small parts of France, Switzerland, Austria and Slovenia and F-E region 493 (Chesapeake Bay Region) includes all of the State of Delaware, plus parts of the District of Columbia, Maryland, New Jersey, Pennsylvania and Virginia. Beginning with January 2000, the 1995 revision to the F-E code has been used in the QED and PDE listings. As an agency of the U.S. Government, we are expected to use the names and spellings approved by the U.S. Board on Geographic Names. Any requests to approve additional names should be made to the U.S. Board on Geographic Names.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: tz

Attribute Definition: Timezone offset from UTC in minutes at the event epicenter.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: tsunami

Attribute Definition: This flag is set to "1" for large events in oceanic regions and "0" otherwise. The existence or value of this flag does not indicate if a tsunami actually did or will exist. If the flag value is "1", the event will include a link to the NOAA Tsunami website for tsunami information. The USGS is not responsible for Tsunami warning; we are simply providing a link to the authoritative NOAA source. See http://www.tsunami.gov/ for all current tsunami alert statuses.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Attribute:

Attribute Label: rms

Attribute Definition: The root-mean-square (RMS) travel time residual, in sec, using all weights. This parameter provides a measure of the fit of the observed arrival times to the predicted arrival times for this location. Smaller numbers reflect a better fit of the data. The value is dependent on the accuracy of the velocity model used to compute the earthquake location, the quality weights assigned to the arrival time data, and the procedure used to locate the earthquake.

Attribute Definition Source: https://earthquake.usgs.gov/data/comcat/

Metadata Reference Information:

Metadata Date: 20200903

Metadata Contact:

Contact Information:

Contact Organization Primary:

Contact Organization: California Department of Conservation

Contact Person: Geographic Information Officer

Contact Address:

Address Type: mailing and physical

Address: 801 K Street, MS 241

City: Sacramento

State or Province: California

Postal Code: 95814

Country: US

Contact Electronic Mail Address: gis@conservation.ca.gov

Metadata Standard name: FGDC Content Standard for Digital Geospatial Metadata

Metadata Standard Version: FGDC-STD-001-1998

Metadata Time Convention: local time