{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "David R Shelly", "hasEmail": "mailto:dshelly@usgs.gov"}, "description": "This Data Release contains an updated version of the San Andreas catalog of low-frequency earthquakes (LFEs):\nShelly, D. R. (2017), A 15 year catalog of more than 1 million low-frequency earthquakes: Tracking tremor and slip along the deep San Andreas Fault, J. Geophys. Res. Solid Earth, 122, 3739\u20133753, doi:10.1002/2017JB014047.\nThis catalog contains 88 LFE families, with each family consisting of events detected by cross-correlation with the associated waveform template.  These templates were identified and located by Shelly and Hardebeck (2010):\nShelly, D. R., and J. L. Hardebeck (2010), Precise tremor source locations and amplitude variations along the lower-crustal central San Andreas Fault, Geophys. Res. Lett., 37, L14301, doi:10.1029/2010GL043672.\nFor completeness, we repeat the original catalog information provided in the supplement of Shelly (2017) below, with minor modifications:\nCatalog Time-Period and Format:\nThe low-frequency earthquake catalog spans from April 2001 to 30 April 2024 and contains 1,528,117 events.\nFormat:  \nYYYY MM DD s_of_day HH mm ss.ss ccsum  meancc med_cc seqday   ID     latitude longitude  depth  n_chan\nExplantions:\nYYYY MM DD (year month day)  - Event time (template start time in UTC - ~1s prior to first S-wave arrival time at an HRSN station)\ns_of_day   - Event time (template start time in UTC - ~1s prior to first S-wave arrival time at an HRSN station), second of the day (i.e. 0-86400),\nHH mm ss.ss (hour, minute, second) - Event time (template start time in UTC- ~1s prior to S-wave arrival time at first HRSN station)\nccsum   - correlation sum across all stations (must exceed 4.0)\nmeancc  - mean correlation among stations with data\nmed_cc  - median correlation\nseqday - sequential day since March 1, 2001\nID     - reference ID of family\nlatitude longitude  depth  - estimated location for that family (Shelly and Hardebeck, 2010)\nn_chan - number of data channels existing for event (some channels may exist, but not have good data)\nFamily IDs:\nEach family has an associated identification code, which is a number followed by 1-4 \u2018s\u2019.  The family IDs are almost meaningless and are simply used as unique identifiers.  Originally the numeric code was taken from the second of the day at which the initial template for this family occurred.  The number of \u2018s\u2019 indicates the number of iterations of stacking and cross-correlation that were applied to derive the template waveforms (see Methods).  The lower amplitude and more distant sources typically benefitted from multiple iterations of stacking and cross correlation, before the final template stabilized in its detection set.\nData channels Used (station.channels):\nGHIB.13, EADB.123, JCSB.1, FROB.123, JCNB.123, VCAB.123, MMNB.123, CCRB.123, LCCB.123, SMNB.123, RMNB.123, SCYB.123\nJCNB failed in 2008 and was replaced by a shallow sensor.  New sensor not used.\nRMNB failed in 2011 and was not replaced.\nGHIB.2 was never operational\nJCSB.23 have poor signal to noise and are not used.\nVARB was replaced with a new sensor at a new depth in 2003, and this station was not used in original template formation.\nAs of 2024, detection capabilities were substantially degraded with a maximum of 16 channels of data available for detection.  This is due to outages in GHIB (since 2020), FROB (since 2023), VCAB (since 2023), and CCRB (since 2022), in addition to the outages described above. It is unclear when/if these stations might be repaired in the future.\nChannel swap on FROB, VCAB (after BP->SP channel swap, before 2011-7-14):\n2011/4/21-2011/7/14:  Swap VCAB.2 and VCAB.3\n2010/11/10-2011/7/14:  Swap FROB.2 and FROB.3\nDisregard mean correlation, enforce network correlation sum only (because of poor but present data):  2012/2/13-2014/4/23\nPolarity corrections during initial processing:\nCCRB.123, correct for reversed polarity from 2001-6-1 to 2001-12-13.\nFROB.123, correct for reverse polarity from 2010/12/10-2011/4/7\nMMNB.123, correct for reverse polarity from 2010/12/10-2011/4/7\nFROB.23, correct for reverse polarity from 2010/4/8 to 2011-7-14\nPolarity corrections applied in post-processing (these are minor and done after initial detection stage):\n2011-4-7 to 2011-5-27:  zero FROB.2 channel (wiring mistake, FROB.2 duplicates FROB.3)\n2005/4/11-2005/5/13: reverse GHIB.13\n2005/12/15-present: reverse GHIB.3\n2002/11/22-2003/1/16: reverse EADB.2\n2002/11/21-2003/1/17: reverse VCAB.3", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P13CPJFU", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.67069991d34ef5df0d802308.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_67069991d34ef5df0d802308", "keyword": ["GHSC", "Golden", "USGS", "USGS:67069991d34ef5df0d802308", "earthquake", "earthquake hazards", "epicenter", "plate tectonics", "seismic"], "modified": "2024-10-21T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-121.1000, 35.4000, -120.0000, 36.5000", "theme": ["geospatial"], "title": "An Updated Catalog of Low-Frequency Earthquakes Along the San Andreas Fault Near Parkfield, California"}