Reference materials for Black Canyon City quakes

The following online maps and reports are getting lots of attention in the wake of the three earthquakes last night - M3.2,M4.1, & M4.0 - near Black Canyon City, about 45 miles north of Phoenix.   All of these are online for free viewing or downloading.

Pearthree, P.A., 1998, Quaternary Fault Data and map for Arizona. Arizona Geological Survey Open File Report, OFR-98-24, 1 map sheet, map scale 1:750,000, 122 p.  http://repository.azgs.az.gov/uri_gin/azgs/dlio/206

Pearthree, P.A., 2011, Big Chino Fault, Chino Valley, Arizona - Video. Arizona Geological Survey Open File Report, OFR-11-08, 6-minute video. The video is published at the Arizona Geological Survey's azgsweb's YouTube channel. http://www.youtube.com/user/azgsweb 

Conway F.M. and Young, J.J, 2012, Arizona is Earthquake Country. Arizona Geological Survey Down to Earth DTE # 21, 44 p.  http://repository.azgs.az.gov/uri_gin/azgs/dlio/1459

Leighty, R.S., 2007, Geologic Map of the Black Canyon City and Squaw Creek Mesa Area, Central Arizona: Arizona Geological Survey Contributed Map CM-07-A, map scale 1:24,000, 46 p. and 1 map sheet.  http://repository.azgs.az.gov/uri_gin/azgs/dlio/1115

Ferguson, Charles A., Haddad, David E., Johnson, Brad J., Guynn, Jerome L., Spencer, Jon E., Eddy, David L., and Clark, Ryan J., 2008, Geologic Map of the east half of the Black Canyon City 7.5’ Quadrangle and the west half of the Squaw Creek Mesa 7.5’ Quadrangle, Maricopa County, Arizona: Arizona Geological Survey Digital Geologic Map DGM-64, version 1.0, map scale 1:24,000, 27 p. and 1 map sheet.  http://repository.azgs.az.gov/uri_gin/azgs/dlio/617

Black Canyon City Earthquake Sequence

The Arizona Geological Survey (AZGS) and Northern Arizona University operate several seismometers throughout the state.  Using 15 stations, 5 of which are not currently used by the National Earthquake Information Center run by the USGS, AZGS has refined the locations for the foreshock, mainshock and the large aftershock from the November 2^nd [using UTC time - using local time, the events were on Nov. 1] Black Canyon City sequence of quakes (Table below).  The M3.2 foreshock was located at approximately 5km north of Black Canyon City at a very shallow depth, between 1-5km.  The mainshock was located approximately 18km NNE of Black Canyon City and occurred at approximately 11km depth.  The largest aftershock an Mw 4.0 occurred only 20 minutes following the mainshock at a depth of approximately 5km.  There have been multiple smaller aftershocks, but there are not enough seismometers close enough to the area of the sequence to accurately locate them.  The closest station is located near Payson at about 65km, with the Wickenburg station being 88km away.  

 

The closest known active fault is the Horseshoe Fault, located 35km SSE of the mainshock.  The Black Canyon City Sequence has not generated a quake large enough to break the surface.  Aftershocks will continue for several months or longer. 

The table below lists the revised locations, and the extent of possible errors in location, horizontally (ERH) and vertically (ERZ).

Mw	Time -UTC	Date	Lat	Long	Depth (km)	RMS (Seconds)	ERH (km)	ERZ (km)
3.2	03:59.33	11-02-15	34.11016	-112.1460	<1 .0="" p="">	0.16	1.05	5.27
4.1	06:29.66	11-02-15	34.23350	-112.12366	11.2	0.07	1.01	3.18
4.0	06:49.32	11-02-15	34.17950	-112.08633	5.19	0.10	0.83	2.77

Post from Dr. Jeri Young, AZGS