Column Labels
Time: The time of the earthquake, reported as the
number of milliseconds since the Unix epoch (January 1, 1970, 00:00:00
UTC).
Latitude: The latitude of the earthquake’s
epicenter, reported in decimal degrees.
Longitude: The longitude of the earthquake’s
epicenter, reported in decimal degrees.
Depth: The depth of the earthquake, reported in
kilometers.
Mag: The magnitude of the earthquake, reported on
various magnitude scales (see magType column below).
MagType: The magnitude type used to report the
earthquake magnitude (e.g. “mb”, “ml”, “mw”).
Nst: The total number of seismic stations used to
calculate the earthquake location and magnitude.
Gap: The largest azimuthal gap between azimuthally
adjacent stations (in degrees).
Dmin: The distance to the nearest station in
degrees.
Rms: The root-mean-square of the residuals of the
earthquake’s hypocenter location.
Net: The ID of the seismic network used to locate
the earthquake.
Id: A unique identifier for the earthquake
event.
Updated: The time when the earthquake event was
most recently updated in the catalog, reported as the number of
milliseconds since the Unix epoch.
Place: A human-readable description of the
earthquake’s location.
Type: The type of seismic event (e.g. “earthquake”,
“quarry blast”, “explosion”).
HorizontalError: The horizontal error, in
kilometers, of the location reported in the latitude and longitude
columns.
DepthError: The depth error, in kilometers, of the
depth column.
MagError: The estimated standard error of the
reported earthquake magnitude.
MagNst: The number of seismic stations used to
calculate the earthquake magnitude.
Status: The status of the earthquake event in the
USGS earthquake catalog (e.g.mb: Body-Wave Magnitude, used for smaller
to medium-sized earthquakes, measuring the amplitude of body waves.
LocationSource: The ID of the agency or network
that provided the earthquake location.
MagSource: The ID of the agency or network that
provided the earthquake magnitude.
Additional magType label definitions:
ml: Local Magnitude (Richter Scale), common for
local, smaller earthquakes, measuring seismic wave amplitude.
mw: Moment Magnitude Scale, the most commonly used
for larger earthquakes, based on the total energy released.
ms: Surface-Wave Magnitude, suitable for moderate
to large earthquakes, focusing on surface wave amplitude.
Other Variants (MwL, Md, Mwr, Mwc, Mwb, Mww): These are specialized
versions of the Moment Magnitude Scale, each adjusted to measure
specific aspects or types of seismic waves.