Alphabetical Glossary of Event Terms

Event Terms

Metadata Terms

Product Terms

Event Terms

alert
Data Type
String
Typical Values
“green”, “yellow”, “orange”, “red”.
Description
The alert level from the PAGER earthquake impact scale.
cdi
Data Type
Decimal
Typical Values
[0.0, 10.0]
Description
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.
code
Data Type
String
Typical Values
"2013lgaz", "c000f1jy", "71935551"
Description
An identifying code assigned by - and unique from - the corresponding source for the event.
depth
Data Type
Decimal
Typical Values
[0, 1000]
Description
Depth of the event in kilometers.
detail
Data Type
String
Description
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.

dmin
Data Type
Decimal
Typical Values
[0.4, 7.1]
Description
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.
felt
Data Type
Integer
Typical Values
[44, 843]
Description
The total number of felt reports submitted to the DYFI? system.
gap
Data Type
Decimal
Typical Values
[0.0, 180.0]
Description
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.
id
Data Type
String
Typical Values
A (generally) two-character network identifier with a (generally) eight-character network-assigned code.
Description
A unique identifier for the event. This is the current preferred id for the event, and may change over time. See the "ids" GeoJSON format property.
ids
Data Type
String
Typical Values
",ci15296281,us2013mqbd,at00mji9pf,"
Description
A comma-separated list of event ids that are associated to an event.
latitude
Data Type
Decimal
Typical Values
[-90.0, 90.0]
Description
Decimal degrees latitude. Negative values for southern latitudes.
longitude
Data Type
Decimal
Typical Values
[-180.0, 180.0]
Description
Decimal degrees longitude. Negative values for western longitudes.
mag
Data Type
Decimal
Typical Values
[-1.0, 10.0]
Description
The magnitude for the event. Learn more about magnitudes.
magType
Data Type
String
Typical Values
“Md”, “Ml”, “Ms”, “Mw”, “Me”, “Mi”, “Mb”, “MLg”
Description
The method or algorithm used to calculate the preferred magnitude for the event. Learn more about magnitude types.
mmi
Data Type
Decimal
Typical Values
[0.0, 10.0]
Description
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.
net
Data Type
String
Typical Values
ak, at, ci, hv, ld, mb, nc, nm, nn, pr, pt, se, us, uu, uw
Description
The ID of a data contributor. Identifies the network considered to be the preferred source of information for this event.
nst
Data Type
Integer
Description
The total number of Number of seismic stations which reported P- and S-arrival times for this earthquake.
place
Data Type
String
Description
Textual description of named geographic region near to the event. This may be a city name, or a Flinn-Engdahl Region name.
rms
Data Type
Decimal
Typical Values
[0.13,1.39]
Description
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.
sig
Data Type
Integer
Typical Values
[0, 1000]
Description
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.
sources
Data Type
String
Typical Values
",us,nc,ci,"
Description
A comma-separated list of network contributors.
status
Data Type
String
Typical Values
“AUTOMATIC”, “PUBLISHED”, “REVIEWED”
Description
Indicates whether the event has been reviewed by a human.
time
Data Type
Long Integer
Description
Time when the event occurred. Times are reported in milliseconds since the epoch . In certain output formats, the date is formatted for readability.
tsunami
Data Type
Integer
Description
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.

type
Data Type
String
Typical Values
“earthquake”, “quarry”
Description
Type of seismic event.
types
Data Type
String
Typical Values
",cap,dyfi,eq-location-map,general-link,geoserve,nearby-cities,origin,p-wave-travel-times,phase-data,scitech-link,tectonic-summary,"
Description
A comma-separated list of product types associated to this event.
tz
Data Type
Integer
Typical Values
[-1200, +1200]
Description
Timezone offset from UTC in minutes at the event epicenter.
updated
Data Type
Long Integer
Description
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.
url
Data Type
String
Description
Link to USGS Event Page for event.

Metadata Terms

api
Data Type
String
Description
Version of API that generated feed.
count
Data Type
Integer
Description
Number of earthquakes in feed.
generated
Data Type
Long Integer
Description
Time when the feed was most recently updated. Times are reported in milliseconds since the epoch.
title
Data Type
String
Typical Values
"USGS Magnitude 1+ Earthquakes, Past Day", "USGS Magnitude 4.5+ Earthquakes, Past Month"
Description
The title of the feed.
url
Data Type
String
Description
Url of the feed.
status
Data Type
Integer
Description
HTTP status code of response.

Product Terms

content
Data Type
Object
Description
A file or group of bytes associated with a product.
contentType
String mime type of this content
lastModified
Millisecond timestamp when this content was modified.
length
Integer number of bytes in this content.
<path>
String relative path within this product, frequently a filename.
url
Link to download this content. When <path> is empty (""), there will be bytes property with content inline.
id
Data Type
String
Description
Unique identifier for a specific version of a product. The id is made of of these four attributes:
source
The product contributor, usually a network code.
type
The type of product. See http://ehppdl1.cr.usgs.gov/userguide/products/ for a list of product types.
code
A unique identifier from the product source, for this type of product.
updateTime
A millisecond timestamp that indicates when this version of the product was created.

Two products with the same source, type, and code, with different updateTimes indicate different versions of the same product The latest updateTime for a product supersedes any earlier updateTime for the same product.

Data Type
String
Description
Products have zero or more links, which consist of:
<relation>
Relation describes how the link is related to the product.
href
Link is a URI, and may be a URL or a URN depending on product type and relation.
Links vary depending on product type.
property
Data Type
String
Description
Products have zero or more key/value properties, which are both Strings. Properties vary depending on product type.
preferredWeight
Data Type
Integer
Description
Relative weight of product. When multiple products of the same type are associated to an event, one product of each type is considered "most preferred". This is defined as the product of that type with the largest preferredWeight, and when two products have equal preferredWeight the most recent updateTime is more preferred.
status
Data Type
String
Description
Status of the product. There is only one reserved status DELETE, which indicates the product has been deleted. Any other value indicates a product update, and may vary depending on product type.