SUMMARY

Search for events by region, magnitude and date

SYNTAX

EVENT {MAG min [max]}
    {TIME start end}
    {REGION w e s n}
    {RADIAL lon lat min_radius max_radius}
    {DEPTH min max}
    {OUTFILE filename}
    {TO blackboard-variable}
    {GCMT|ISC|NEIC|CMT|USGS|PDE}
    {VERBOSE}

INPUT

TIME: Set the start and end times. End times can be set relatively.

REGION west east south north:

Set the geographic bounds of the search region

RADIAL min max: Set the center and radius limits of the search region in degrees

DEPTH min max: Set the minumum and maximum depth values in km.

MAG min [max]: Set the minimum and maximum magnitude values. A single value can be used to set a minimum magnitude and the maximim magnitude is set to 10.0.

GCMT: Search the Global Centroid Moment Tensor Catalog, CMT is an alias

ISC: Search the ISC Catalog

USGS: [Default] Search the USGS Catalog, PDE and NEIC are aliases

TO blackboard-variable:

Save all event identifiers to a space separated list with a specific name

OUTFILE: Save the event search into a file. Files ending in .xml are saved as QuakeXML documents; those ending in .txt and others are saved as "csv" text

VERBOSE: [Not default] Watch the details of the event search process

TIME:	Set the start and end times. End times can be set relatively.
REGION west east south north:
	Set the geographic bounds of the search region
RADIAL min max:	Set the center and radius limits of the search region in degrees
DEPTH min max:	Set the minumum and maximum depth values in km.
MAG min [max]:	Set the minimum and maximum magnitude values. A single value can be used to set a minimum magnitude and the maximim magnitude is set to 10.0.
GCMT:	Search the Global Centroid Moment Tensor Catalog, CMT is an alias
ISC:	Search the ISC Catalog
USGS:	[Default] Search the USGS Catalog, PDE and NEIC are aliases
TO blackboard-variable:
	Save all event identifiers to a space separated list with a specific name
OUTFILE:	Save the event search into a file. Files ending in .xml are saved as QuakeXML documents; those ending in .txt and others are saved as "csv" text
VERBOSE:	[Not default] Watch the details of the event search process

DEFAULT VALUES

EVENT USGS

DESCRIPTION

Search an catalog for events. Results are returned to the screen or to a file if desired with the OUTPUT filename option.

Time ranges can be set using a variety of formats, see examples below. End times can be set using a relative value with units. See DATA ACCESS for time formats.

Event IDs are saved and can be used to identify origin times and locations in similar searching commands. They can also be used to set SAC file METADATA for an event.

EXAMPLES

To search for all events with Magnitudes \(\ge\) 9.0:

SAC> event mag 9
Origin              Lat.   Lon.    Depth  Mag.     Agency EventID
2011-03-11T05:46:24  38.30  142.37  29.00 9.10 mww US/official
usgs:official20110311054624120_30
2004-12-26T00:58:53   3.29   95.98  30.00 9.10 mw  US/official
usgs:official20041226005853450_30
1964-03-28T03:36:16  60.91 -147.34  25.00 9.20 mw  iscgem/official
usgs:official19640328033616_30
1960-05-22T19:11:20 -38.14  -73.41  25.00 9.50 mw  iscgem/official
usgs:official19600522191120_30
1952-11-04T16:58:30  52.62  159.78  21.60 9.00 mw  iscgem/official
usgs:official19521104165830_30

If you were expecting to find a specific event, it can be useful to search different catalogs. Let's use the UGSS / NEIC Catalog:

SAC> event mag 9 cmt
Origin              Lat.   Lon.    Depth  Mag.     Agency EventID
2011-03-11T05:47:32  37.52  143.05  20.00 9.10 MW  GCMT/- gcmt:3279407
2004-12-26T01:01:09   3.09   94.26  28.60 9.00 MW  GCMT/- gcmt:1916079

Let's try to focus into 1960 Chile by searching the southern hemisphere. Note, longitudes should be between -180 and 180:

SAC> event mag 9 usgs region -180 180 -90 0
Origin              Lat.   Lon.    Depth  Mag.     Agency EventID
1960-05-22T19:11:20 -38.14  -73.41  25.00 9.50 mw  iscgem/official
usgs:official19600522191120_30

Consider the deep 1994 Bolivian earthquake. Let's limit the depth and restrict the time range:

SAC> event time 1994-1 +1yr mag 8 usgs depth 610 1000
Origin              Lat.   Lon.    Depth  Mag.     Agency EventID
1994-06-09T00:33:16 -13.84  -67.55 631.30 8.20 mw  US/HRV usgs:usp0006dzc

Consider the 1989 Loma Prieta Earthquake in Northern California. This time we use a radial search between 0 and 5 degrees around 120 W, 38 N:

SAC> event time 1989-1 +1yr mag 6 radial -120 38 0 5
Origin              Lat.   Lon.    Depth  Mag.     Agency EventID
1989-10-18T00:04:15  37.04 -121.88  17.21 6.90 mh  NC/NC usgs:nc216859

Event Identifiers (eventid)

Events can be referenced in other commands using a unique identifier. The identifier is defined by source:uniqueid. Where the source is defined below and the unique identifer is the reference id provided by the agency. Most identifiers are less than 16 characters and will fit into the KEVNM header variable; the official catalog of significant earthqukes is a notable execption.

Source	Catalog
isc	International Seismological Centre	http://www.isc.ac.uk/
usgs	United States Geological Survey	https://earthquake.usgs.gov/
gcmt	Global Centroid Moment Tensor	https://www.globalcmt.org/

EVENT