EARTHQUAKE & PHASE
INPUT DATA SET
There is currently one searchable earthquake catalog (SCSN) available.
January 1, 2001.
These are earthquakes located by the Southern California Seismic Network (SCSN) from 1932-present.
There are currently eight output formats available from this catalog search.
Click on the underlined links below to see the specifics about data formats.
This format is an easy-to-read table containing the basic event
such as time, hypocenter, depth, magnitude, type of magnitude, type of
number of stations, etc. This is the most readable output, and should
be used for all preliminary searches.
Caltech "catread" (SCSN) format
Simpson Map (Recent Earthquakes Map) format
Hypoinverse format year 2000
Hypo71 format year 2000
Hypoinverse phase format
This will return the phase arrival entries for the selected entries from the SCSN phase catalog.
Note that the phase data may take 100x more lines than the catalog entries.
EVENT ID #
The event identification number is a unique number assigned to every event in the SCEDC catalog. This number
is soley used by the SCEDC catalog. In other words, the same event may have a different id number in another
To query for more than one event, separate each event id with a comma. Example: event1, event2, event3
The date parameters are specified in the following format:
year= year (1999-present)
mm = month (1-12)
dd = day-of-month(1-31)
Time is in UTC time
hr = hour(1 - 24)
min = min(1 - 60)
sec = sec(1 - 60)
The date must be fully specified. If not an appropriate error message
will be displayed in your browser
LATITUDE and LONGITUDE PARAMETERS
Latitude and Longitude values are specified in decimal degrees,
e.g. 34.50 for 34 and one-half degrees. Latitude values can
range from -90 to 90, and longitude values can range from -180 to 180.
Remember that longitude for California is WEST, and
therefore should be specified as NEGATIVE (eg -121.5 for 121.5
On the 4-point polygon search, to enter the latitude and longitude parameters
from the map, click on the map at each corner of the desired polygon. The
current latitude and longitude position of the
mouse is echoed on the screen. To move an existing pick to a new coordinate,
press the mouse button while over the
point to be changed and drag it the new position. Clicking on the map always
moves the nearest pick to the selected location. You may also enter the latitude and longitude values manually by typing in the
text regions to the right of the map. After entering the desired values, click
on "Apply" to update the map.
MINIMUM - MAXIMUM PARAMETERS
Search parameters that have min and max values are:
Magnitude - specified in decimal, e.g. 5.7 or 2.6
Depth - specied in decimal kilometers, e.g. 6.0 or 300.0
EVENT TYPE DESCRIPTION
Additional search parameters for selecting earthquakes
include the following event type specifications.
eq - Earthquake: Seismic event within or close to the SCSN authoritative region. The event is futher qualified by geographic type or gtype. See geographic type description.
qb - Quarry blast: Event is an explosion associated with work at a
quarry. In historical catalog, this may also include other types of
explosions, such as seismic surveys.
nt - Nuclear explosion: Event is an explosion at a nuclear test site.
ex - Explosion: Event is an explosion from an unknown cause.
sh - Shot: Event is an explosion that is part of a seismic survey.
sn - Sonic Boom: Event is from a sonic shock wave.
st - Subnet Trigger: Event detected by network triggering algorithm. To be determined by analysts if energy is seismic.
th - Thunder: Event is associated with a thunder storm.
uk - Unknown: Event of an indeterminate type or very badly located event. Rarely used in current catalog.
GEOGRAPHIC TYPE DESCRIPTION
Additional search parameter for further qualifying earthquakes.
l - Local event: Earthquake within the SCSN authoritative region.
In cases where a sequence or large event occurs near the border,
local events could exist 10-25km (0.1 to 0.2 degrees) beyond the official
boundary for catalog completeness.
r - Regional event: Seismic event occurred outside the network boundary in neighboring network. Location quality may not be refined by the SCSN.
t - Teleseismic event: Seismic event occurred at a distance greater than 1,000km from closest SCSN station.