1999 Hector Mine earthquake

Magnitude 7.1 earthquake in California May 2025 February 2025 1999 Hector Mine earthquake USA California 1999-10-16 09:46:45 1643776 ci9108652 1999 10 16 02:46:45 PDT 7.1 w y 20 km mi 0 on Southern California United States 34.54 -116.39 region:US_type:event inline,title Strike-slip Limited VII 4–5 injured The 1999 Hector Mine earthquake occurred in Southern California, United States, on October 16 at 02:46:50 PDT. Its moment magnitude was 7.1 and the earthquake was preceded by 12 foreshocks, the largest of which had a magnitude of 3.8. The event is thought to have been triggered by the 1992 Landers earthquake which occurred seven years earlier. It also deformed nearby faults vertically and horizontally. The earthquake's hypocenter was at a depth of 20 kilometers and its epicenter at 34.603° N 116.265° W.https://earthquake.usgs.gov/earthquakes/eventpage/ci9108652/origin/detail M 7.1 – Hector Mine, CA Earthquake 2021-11-30 United States Geological Survey 2021-11-30 https://web.archive.org/web/20211130031249/https://earthquake.usgs.gov/earthquakes/eventpage/ci9108652/origin/detail live The earthquake caused minimal damage and no fatalities due to the distance of its epicenter from populated centers. The significance of this earthquake lies in the fact that, firstly, it had a relatively-high magnitude but caused little damage and secondly, it offered more evidence that stress accumulation over time causes earthquakes. Precursor events thumb|A visual representation of a right-lateral strike slip fault It is thought that the 1999 Hector Mine earthquake may have been triggered by the 1992 Landers earthquake seven years prior, since the recurrence interval of large earthquakes in the Eastern California Shear Zone is considered to be in the order of thousands of years.Robert J. Mellors Lydie Sichoix David T. Sandwell Lack of Precursory Slip to the Hector Mine Earthquake as constrained by INSAR http://topex.ucsd.edu/mellors/mellors_text.pdf dead https://web.archive.org/web/20100701194503/http://topex.ucsd.edu/mellors/mellors_text.pdf 2010-07-01 2009-10-21Evelyn J. Price Roland Bürgmann 2002 Interactions between the Landers and Hector Mine, California, Earthquakes from Space Geodesy, Boundary Element Modeling, and Time-Dependent Friction http://bssa.geoscienceworld.org/cgi/content/abstract/92/4/1450 live The Bulletin of the Seismological Society of America 92 4 1450 2002BuSSA..92.1450P 10.1785/0120000924 https://web.archive.org/web/20110724152734/http://bssa.geoscienceworld.org/cgi/content/abstract/92/4/1450 2011-07-24 2009-10-21 subscription That event had a magnitude of 7.3, similar to the Hector Mine quake, was also a strike slip event.Pollitz Fred Sacks Selwyn May 1, 2002 Stress Triggering of the 1999 Hector Mine Earthquake by Transient Deformation Following the 1992 Landers Earthquake https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/92/4/1487/120795/Stress-Triggering-of-the-1999-Hector-Mine live November 29, 2021 Bulletin of the Seismological Society of America https://web.archive.org/web/20211130024019/https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/92/4/1487/120795/Stress-Triggering-of-the-1999-Hector-Mine 2021-11-30 Another reason why the Landers earthquake is likely to have triggered the Hector Mine earthquake as they both occurred 20 kilometers apart.Felzer Karen R. Karen Felzer Becker Thorsten W. Abercrombie Rachel E. Ekström Göran Rice James R. 2002 Triggering of the 1999 MW 7.1 Hector Mine earthquake by aftershocks of the 1992 MW 7.3 Landers earthquake https://onlinelibrary.wiley.com/doi/abs/10.1029/2001JB000911 Journal of Geophysical Research: Solid Earth 107 B9 ESE 6–1–ESE 6–13 10.1029/2001JB000911 2002JGRB..107.2190F 2156-2202 subscription The Hector Mine earthquake is thought to be an example of increased fault stress from a separate quake which built over seven years until finally rupturing in 1999. As a result, studying of the Landers earthquake became quite important in understanding this new earthquake near the turn of the century. Foreshocks During a fault rupture, stress is released as two sides of fault slip and move past each other. Stress can be transferred from one fault to adjacent faults, causing subsequent fault ruptures. By nature, foreshocks are not possible to identify as such until after the main shock or largest magnitude of shaking occurs. For this reason, they can not be used to predict larger earthquakes or give warnings to residents of the affected area. That being said, it was determined after the fact that a sequence of twelve foreshocks preceded the Hector Mine main shock. These foreshocks progressed northward 20 hours before the mainshock, and occurred in the same location as a cluster of off-fault aftershocks of the 1992 Landers earthquake.SCEDC – Hector Mine Earthquake http://www.data.scec.org/significant/hectormine1999.html dead https://web.archive.org/web/20120523185544/http://www.data.scec.org/significant/hectormine1999.html 2012-05-23 2012-03-21 The largest of the twelve foreshocks had a magnitude of 3.8 and occurred at 7:41 PM PDT on the 15th of October.Southern California Earthquake Data Center at Caltech https://scedc.caltech.edu/earthquake/hectormine1999.html 2021-10-15 Southern California Earthquake Data Center Earthquake thumb|Map showing the relative location of the 1999 Hector Mine Earthquake and its foreshocks. This strike-slip earthquake occurred in a remote part of the Mojave Desert, 47 mi km east-southeast of Barstow, California, inside the Twentynine Palms Marine Corps Base. Strike-slip faults are fractures where the blocks have mostly moved horizontally. If the block under the right foot of the observer straddling the fault moves towards the observer, the slip style is termed right lateral; if the block under the observer's left foot moves towards the observer, the fault is termed left lateral.Eric Matthys 2014 Strike-Slip Fault https://www.usgs.gov/media/videos/strike-slip-fault 21 October 2021 United States Geological Survey 20 October 2021 https://web.archive.org/web/20211020182418/https://www.usgs.gov/media/videos/strike-slip-fault live This right-lateral strike-slip quake involved rupturing the Lavic Lake fault and the Bullion Fault. Within the last two months of when it occurred, the 1999 Hector Mine earthquake was one of four earthquakes recorded with a magnitude of 7 or greater.1999-10-17 7.0 Earthquake in Mojave Desert Rocks Southland https://www.latimes.com/archives/la-xpm-1999-oct-17-mn-23272-story.html 2021-10-13 Los Angeles Times The earthquake was one of the strongest to occur during the last 100 years.2019-10-17 20 Years Since the 7.1 Hector Mine Earthquake Rattled the Coachella Valley https://nbcpalmsprings.com/2019/10/16/20-years-since-the-7-1-hector-mine-earthquake-rattled-the-coachella-valley/ 2021-10-15 NBC Palm Springs 2021-10-15 https://web.archive.org/web/20211015230902/https://nbcpalmsprings.com/2019/10/16/20-years-since-the-7-1-hector-mine-earthquake-rattled-the-coachella-valley/ live The event was named after a nearby quarry in the Mojave Desert, located 22 km mi 0 us northwest of the epicenter. Despite its size, it did not cause nearly as much damage compared to the smaller magnitude 6.7 1994 Northridge earthquake due to its remote location from populated areas.1999-10-17 7.0 Earthquake in Mojave Desert Rocks Southland https://www.latimes.com/archives/la-xpm-1999-oct-17-mn-23272-story.html 2021-10-15 Los Angeles Times The earthquake was felt in much of Southern California as well as parts of Arizona and Nevada, including Las Vegas.Southern California Earthquake Data Center at Caltech https://scedc.caltech.edu/earthquake/hectormine1999.html 2021-10-06 Southern California Earthquake Data Center 2021-09-30 https://web.archive.org/web/20210930223131/https://scedc.caltech.edu/earthquake/hectormine1999.html live Further, it awakened many people in Las Vegas with residents reporting dizziness and having trouble walking. The shaking from this seism was felt as far north as Carson City. Damage Almost no damage was reported in the immediate area of the earthquake due to the remote location of the epicenter in the Mojave Desert. The Marine Corps Air Ground Combat Center Twentynine Palms, located in the Mojave Desert, contained the surface rupture of the Hector Mine earthquake. This did not cause extensive damage to the base. Two California highway bridges were also damaged. The biggest report of damage was a derailed westbound Amtrak Southwest Chief train which left rails split up and a total of twenty-one cars completely off the track. The train was traveling near the epicenter when the quake struck. The combined force of the quake and train caused several rails to come loose and fully derail parts of the train. The Amtrak train suffered repairable damage. There were no deaths; only minor injuries were reported, some of which needed treatment. The earthquake did not affect human life on a large scale due to the time at which it occurred: 2:46am. Despite the large magnitude, damage to the area was limited due to the affected region being mostly desert and very sparsely populated. While the earthquake was primarily in the desert, movement could be felt through many parts of California, including Palm Springs. Aftermath An examination of deformation following the earthquake reported horizontal and vertical motion of several millimeters on multiple faults in the vicinity.Southern California Earthquake Data Center at Caltech https://scedc.caltech.edu/about/citation.html 2021-10-15 Southern California Earthquake Data Center 2022-02-08 https://web.archive.org/web/20220208015558/https://scedc.caltech.edu/about/citation.html live The 1999 Hector Mine earthquake resulted in segments of aftershocks in the nearby area. The most notable of them, due to their large magnitudes, occurred several kilometers both north and south to the main shock. These aftershocks were measured to be of magnitude 5.9 and 5.7Hauksson E. 2002-05-01 The 1999 Mw 7.1 Hector Mine, California, Earthquake Sequence: Complex Conjugate Strike-Slip Faulting https://doi.org/10.1785/0120000920 Bulletin of the Seismological Society of America 92 4 1154–1170 10.1785/0120000920 2002BuSSA..92.1154H 0037-1106 The earthquake and its aftershocks resulted in surface deformation of several millimeters vertically and horizontally on many of the surrounding pre-existing faults in the area.Fialko Yuri Sandwell David Agnew Duncan Simons Mark Shearer Peter Minster Bernard 2002-09-13 Deformation on Nearby Faults Induced by the 1999 Hector Mine Earthquake https://www.science.org/doi/abs/10.1126/science.1074671 Science 297 5588 1858–1862 10.1126/science.1074671 12228714 2002Sci...297.1858F 320462 2021-10-19 2021-11-11 https://web.archive.org/web/20211019120638/https://www.science.org/doi/abs/10.1126/science.1074671 live Again, due to the remote location of this earthquake's epicenter, no new precautions needed to be taken or implemented in the aftermath of the 1999 Hector Mine earthquake. However, this earthquake prompted further research into its precursor: the 1992 Landers earthquake which in the same area. See also California 1992 Landers earthquake 2019 Ridgecrest earthquakes List of earthquakes in 1999 List of earthquakes in California List of earthquakes in the United States References Railroad damage from the October 16, 1999 Hector Mine earthquake https://www.arema.org/eseries/scriptcontent/custom/e_arema/library/2001_Conference_Proceedings/00045.pdf W. G. Byers 2001 Burlington Northern and Santa Fe Railway February 8, 2017 https://web.archive.org/web/20120923200056/http://www.arema.org/eseries/scriptcontent/custom/e_arema/library/2001_Conference_Proceedings/00045.pdf September 23, 2012 live ISC-GEM Global Instrumental Earthquake Catalogue (1900–2013) http://www.isc.ac.uk/iscgem/index.php ISC 2017 International Seismological Centre Version 4.0 2017-02-08 https://web.archive.org/web/20161125091901/http://www.isc.ac.uk/iscgem/index.php 2016-11-25 live Significant Earthquake Database https://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1 National Geophysical Data Center / World Data Service (NGDC/WDS) National Geophysical Data Center, NOAA 10.7289/V5TD9V7K 1972 Data Set 2016-03-08 https://web.archive.org/web/20170721203405/https://www.ngdc.noaa.gov/nndc/struts/form?t=101650&s=1&d=1 2017-07-21 dead PAGER-CAT Earthquake Catalog https://earthquake.usgs.gov/static/lfs/data/pager/catalogs/ September 4, 2009 United States Geological Survey Version 2008_06.1 dead https://web.archive.org/web/20161004150402/http://earthquake.usgs.gov/data/pager/catalogs/ October 4, 2016 External links Hector Mine Earthquake – Southern California Earthquake Data Center M7.1 – Southern California – United States Geological Survey 1643776 1999 Hector Mine Hector Mine earthquake Hector Mine earthquake Hector Mine Hector Category:Strike-slip earthquakes Category:October 1999 in the United States