Magnitude 3.7 earthquake is largest one yet in Arizona swarm

There was only one earthquake greater than magnitude 1.0 in the past week in the area of the quake swarm in northwest Arizona until Saturday night when a magnitude 3.7 event struck just after 9 p.m. local time, followed by three apparent aftershocks in less than an hour.  The main event is the largest one yet in the swarm of the past few weeks, surpassing the previous one of M=2.7.   [Right, orange star marks the epicenter of the M=3.7 quake, with contours showing distribution of shaking.   Red lines are active faults.  Credit, USGS]

There are reports of the earthquake being felt in the sparsely populated region.

[Below, magnitudes, location, and time of Saturday night quakes in the swarm area.]

Small quake in Intermountain Seismic Belt south of Utah

A small earthquake, magnitude 2.0 hit in the midst of the active faults of the Intermountain Seismic Belt at 4:28 a.m. Friday morning, just south of the Utah border.  This does not appear to be related to the earthquake swarm of the past couple of weeks going on about 50 km to the southwest.   There have been only a few small events in that area in the past week.  [Right, orange star marks Friday's epicenter. Red lines are active faults. Credit, USGS]

Hunt for helium ramps up in Arizona

Three companies now have active exploration programs underway in Arizona to develop underground helium resources.

Ranger Development, a Texas-based joint venture, made a presentation last Friday to the Arizona Oil & Gas Conservation Commission on their efforts to reopen the Pinta Dome and Navajo Springs helium fields in the Holbrook basin of eastern Arizona.   The fields are at the northern edge of the Holbrook salt basin and potash deposit.   [note, the original post mis-stated the name of the Navajo Springs field]

They described the two fields as some of the richest in the world in terms of percentages of helium in the reservoir.   In most situations, 1% helium is considered economic.  In the Arizona fields, helium accounts for ~8% with the remainder almost entirely nitrogen, according to the Ranger presentation. They said Arizona is the "Saudi Arabia of helium."

The two fields were shut-in in the 1970s due to low prices resulting from the US government selling the gas at a low price from the national reserves rather than the fields being depleted.  Since then, there has been little incentive for the private sector to explore and develop helium resources. However, the US is getting out of the helium business, and extended sales from the reserve while private sources are developed.  There is a global shortage of helium, pushing up prices.  Helium prices are about $90 per thousand cubic feet (MCF) on the spot market, but Ranger said there is a great variability allowing them to sell their product at $125 to as high as $200 per MCF.   They expect to have the processing plant running by May, 2016 to separate the helium from nitrogen and start commercial production.  The plant will handle 2 million cubic feet of gas (MMCF) per day. The primary reservoir target is the Coconino Sandstone, followed by the Supai Formation.

Ranger Development filed permits for wells with the Oil & Gas Conservation Commission for new drilling, and got a spacing exemption for two wells to address local geologic conditions.  They  estimate about 1 billion cubic feet of gas remaining in each of the two fields. 

Meanwhile Blackstone Exploration got permits approved by the Commission for 5 new gas wells in the area, which are expected to target helium as well.  

A third company has advised us that they are getting ready to file their drilling permits.

Earthquake activity ramps up in southeastern Arizona

There have been at least 22 small earthquakes in the last 24 hours south of Duncan in southeastern Arizona, near the New Mexico border, according to Dr. Jeri Young, who manages the state seismic monitoring network here at AZGS.   A magnitude 3.0 earthquake at 8:22 a.m. today is the largest one detected.  There are reports of shaking being felt  by residents in the area.   [Right, orange star marks the epicenter of the M=3.0 event. Credit, USGS]

The earthquakes are occurring in the same area that experienced a magnitude 5.3 quake in June 2014.   Aftershocks have continued in the area since then.

Earthquake in northwest Arizona - magnitude 3.4

There was a magnitude 3.4 earthquake in northwest Arizona at 2:23 a.m. local time this morning.   The preliminary USGS location puts it about 30-40 km east of the ongoing earthquake swarm west of the Grand Wash Cliffs.  We are examining the records to see if adding data from the Arizona seismic network will change the location.   [Right, orange star marks epicenter.  Red lines are active faults, which are part of the Intermountain Seismic Belt. Credit, USGS]

Earthquake swarm continues, M=2.7 is largest one yet

The earthquake swarm in northwest Arizona continues with two events occurring shortly before 1 a.m. this morning, one at magnitude 2.7 and another two minutes later with magnitude 2.2.   The locations are being replotted by Dr.Jeri Young here at AZGS, using data from the Arizona Broadband Seismic Network that we manage.  This could result in the epicenters being revised by a number of kilometers based on previous re-calculations.  [Right, today's quakes are shown in orange. The blue dot is Wednesday's event.  The yellow dots are some of the previous events.  Red lines are active faults. Credit, USGS]

The swarm began March 28 and we now have recorded 22 events, ranging in magnitude 0.7 to today's 2.7.     This is a remote area and there are no reports of anyone feeling the quakes, let alone any damage.   The area sits between the Mesquite and Grand Wash faults, at the eastern edge of the Basin and Range Province which is still stretching east-west, and at southern end of the Intermountain Seismic Belt.

The Arizona seismic network is funded by internal funds generated by the Arizona Geological Survey. We receive no state or federal funds to operate the network or process the data.   

Another small quake today in NW Arizona swarm

We had a magnitude 2.4 earthquake this morning at 10:12 a.m. local time in area between the Mesquite and Grand Wash faults in northwest Arizona along the Nevada border.  This brings the total to 19 events since March 28. This is the second largest quake in the series, with the biggest one at M=2.6.  However, given the remote location, these magnitudes will have some margin of error in location and size.   [Right, orange star marks the epicenter of this latest quake. Credit, USGS]

Meanwhile, our news release on the weekly swarm of earthquakes in the area has been picked up by news media nationwide.    Alexa Liacko, reporter for Tucson's  KGUN channel 9 news, interviewed me this afternoon about the quakes and what it means for Arizonans [below].

Arizona Oil & Gas Conservation Commission continued for 6 years

Gov. Doug Ducey signed SB1059, continuing the Arizona Oil & Gas Conservation Commission for 6 years, until July 1, 2022.  The Sunset Review panel had originally recommended an 8 year continuation but the Arizona House cut that to match the Sunset Review for the Dept. of Environmental Quality.    Gov. Ducey has proposed shifting the duties to provide technical and admin support to the Commission from AZGS to ADEQ, starting July 1, 2016, as part of his consolidation plans which involve transferring the AZGS duties to the University of Arizona.


The Legislative Fact Sheet on the continuation bill states:

In July 1991, the Legislature eliminated the Arizona Oil and Gas Conservation Commission (OGCC) agency and attached the OGCC governing board to the Arizona Geological Survey (AZGS). The OGCC consists of the State Land Commissioner and five members appointed by the Governor, only three of whom may be of the same political party. Appointed members must be United States citizens and Arizona residents of at least five years (A.R.S. § 27-514).

The OGCC administers and enforces state laws with the purpose of: 1) conserving and preventing waste of oil, gas and geothermal resources; 2) providing for protection of owners of land wherein these resources lie; 3) encouraging responsible development of these resources; 4) encouraging a continuous and economic supply of and demand for these resources; and 5) safeguarding the health, property, environment and public welfare of the citizens of this state (A.R.S. § 27-502).

The OGCC fulfills its mission by: 1) issuing permits for oil, gas and geothermal wells; 2) monitoring and inspecting wells and facilities for compliance with rules; 3) maintaining rules; 4) compiling and maintaining drilling, production and subsurface data for public use; 5) coordinating enforcement with the Attorney General; and 6) preparing and publishing geologic studies to encourage exploration for and development of Arizona’s oil, gas and geothermal resources.

Update on northwest Arizona earthquake swarm - 19 events so far

 On March 29th, a magnitude (ML) 2.3 earthquake occurred about 23 miles south-southwest of Littlefield, Arizona. This event marked the onset of a swarm of 18 small magnitude earthquakes that continued through April 3rd. The largest event, ML 2.6, occurred at 8:36 am on April 3rd. There were no reports of damage or injuries.  [Top right. The location of the 19 seismic events in northwestern Arizona; red circles with magnitudes of each event; red lines show location of known, active faults; vertical white line is the NV-AZ border. Background image by Google Earth.]

The magnitude, date, and location of events are tabled below. The Google Earth map shows the locations of individual events which form a distinctly northwest trend. Also included for the ML 2.6 event are seismograms from the Arizona Geological Survey’s Arizona Broadband Seismic Network.

Active faults in the vicinity of the earthquake swarm include the Mesquite/Overton Arm, about 10 miles north along the western front of the Virgin Mountains, and the Grand Wash Fault system 11 miles to the east. The latter represents the boundary between the Colorado Plateau and the Basin and Range Provinces, an area with extensive historical earthquake activity.

Both fault systems are normal faults with down-dropping western blocks, characteristic of many active faults in the Basin and Range Province of northwestern Arizona and Nevada.

The northwest trend of this earthquake swarm (see above) is similar to other earthquake sequences observed in central and northern Arizona. In addition, strong lineaments in the nearby landscape suggests that there are potentially active faults immediately north of the largest event. More investigative mapping is needed to determine if the lineaments in the general area are indeed active faults.  

The 2.0+ events were resolved from data of the Arizona Integrated Seismic Network, while the small magnitude events were approximately located by the Nevada Seismological Laboratory. The small magnitude and dearth of seismometers in this remote area precludes more precise locations. Calculating depths of the individual events in northwestern Arizona’s rugged terrain was similarly difficult, resulting in a broad range of depths from 0.0 miles to 8.6 miles.  [Bottom right, seismograms from AZ stations for the ML 2.6 April 3rd event.]

Over the past 22 months, moderate-size earthquakes have been reported in the Phoenix area - the Black Canyon City ML 4.1 and 4.0 events on the night of Nov. 2, 2015, which were felt widely in the Valley of the Sun; the Kachina Village ML 4.7 event of Nov. 30, 2015, felt in both Sedona and Flagstaff; and the ML 5.3 earthquake that rattled Duncan in eastern Arizona and resulted in aftershocks that were felt more than one year after the main shock. 


Table of earthquake events associated with the Mesquite swarm in northwestern Arizona,
29 March – 3 April 2016

Most Recent to Oldest	Earthquake Date	Magnitude (ML)	Latitude (N)	Longitude (W)
1	04/04/2016	1	36.489	113.989
2	04/03/2016	1.1	36.514	114.024
3	04/03/2016	2.6	36.456	113.979
4	04/03/2016	0.7	36.521	114.031
5	04/03/2016	1.1	36.481	113.971
6	04/03/2016	1.1	36.489	113.971
7	04/03/2016	1.0	36.489	113.989
8	04/02/2016	1.2	36.488	113.987
9	04/02/2016	1.0	36.473	113.979
10	04/02/2016	1.7	36.492	113.998
11	04/01/2016	1.5	36.493	114.002
12	04/01/2016	2.0	36.498	113.992
13	03/31/2016	1.6	36.486	113.922
14	03/30/2016	1.0	36.524	114.014
15	03/30/2016	1.7	36.439	113.969
17	3/29/2016	1.6	36.506	114.004
18	3/29/2016	0.8	36.483	114.004
19	3/29/2016	2.3	36.54	114.013

This material taken from a report prepared by Dr. Jeri, Young, AZGS, and posted at http://www.azgs.az.gov/news_releases2016.shtml#apr5

Revised locations for earthquake swarm in northwest Arizona

The first 8 earthquakes in this week's swarm in northwest Arizona have been relocated by Dr. Jeri Young at AZGS using our local seismograph stations to improve accuracy from the USGS regional network.    The vertical white line in the figure at right is the Nevada-Arizona border.   Magnitudes of the quakes are shown in white.

The Mesquite and Grand Wash faults are shown in red.

Three more quakes occurred in the area after this figure was prepared.

Three more quakes in swarm in area of known faults

There were three more small earthquakes in northwest Arizona along the Nevada border on Friday, bringing the total to 11 since March 28.

The most recent ones were:
Magnitude 2.0 at 11:41 a.m.
Magnitude 1.5 at 12:01 p.m.
Magnitude 1.7 at 8:45 p.m.   (all in local times)

USGS geologist George Billingsley's map of area shows the Coxcomb, a long ridge at the southern extreme of the area hit by this recent seismicity [right]. The yellow circle encompasses some of the 1.0 M events.  The M2.0+ events are just off the map to the NNW.

World's tiniest dinosaur remarkably well preserved

The world's smallest dinosaur has been recovered from the waste rock pile outside an old mine adit in northwestern Arizona.   The distant cousin of the famous Tyrannosaurus-Rex ("T-Rex") would have weighed less than a pound when alive, according to discoverer, Gil Davidson, author of the scientific paper published today in the International Bulletin of Economic Taphonomy (IBET).

Davidson noted the specimen, which paleontologists have dubbed "T-Minus", is completely preserved, apparently through an unknown chemical process in the rocks.

Exploration is underway for other specimens at the site, which is next to an elementary school playground.


[This is our post for April 1 and we stand by it.]

Earthquake "swarm" continues along Arizona - Nevada border

There have been 7 earthquakes recorded in northwest Arizona along the Nevada border during the past few days.  The latest one of magnitude 1.0 occurred around 4 pm local time yesterday (March 30).  The largest one was a magnitude 2.3 on March 28.   The smallest one is only magnitude 0.8.

The cluster is visible on the map south of Mesquite.  [Credit, USGS]

Aftershock to yesterday's small quake on Arizona - Nevada border

There was a magnitude 2.0 earthquake at 2:55 a.m. local time this morning close to yesterday's M=2.3 and 1.8 quakes.    Was this an aftershock?    I'm not used to seeing earthquakes as small as M=2.3 generating aftershocks, so it may be just coincidence.   [Right, today's epicenter marked by orange star. Credit, USGS]

Senate vote imminent on geologist de-licensing bill

An email sent out to Arizona members of AIPG reports that the bill to eliminate licensing of geologists and other professions in Arizona (HB2613) is set to be discussed in Senate Caucus today and could be voted on by the entire Senate by Wednesday or Thursday this week.

AIPG, other local professional associations, and industry groups are attempting to amend the bill to remove geologists from it.  

In a related action, the Senate Commerce and Workforce Development Committee adopted an amendment removing the requirement that the State Geologist of Arizona must be registered. Instead anyone meeting the requirements of a "trained geologist" can be appointed to the position.   A 'trained geologist" means a person who has:

1.  earned a geology degree from an accredited educational institution

2. participated in geological work experience outside of an educational institution for at least four years

Two small quakes along Nevada border

A magnitude 2.3 earthquake occurred along the Arizona-Nevada border this morning at 5:11 a.m. local time, followed by a magnitude 1.8 event (aftershock?) just over an hour later, and just southeast of the first event.  [Right, orange star marks epicenter of the main shock.  Credit, USGS]

Op-ed supports preservation of AZGS mission, services

Tucson-based consulting geologist David Briggs published an opinion piece in the Arizona Independent newspaper urging the preservation of the services and products of the Arizona Geological Survey, in response the Gov. Ducey's plan to transfer our duties to the University of Arizona, effective this coming July 1.

David's concluding  paragraph states:

In January 2016, Arizona Governor Doug Ducey released his Proposed Executive Budget for Fiscal Year 2017, where he recommended consolidating the AZGS with the University of Arizona.  This proposed restructuring of state government has raised concerns among many in the Arizona’s geological community, who fear it will severely limit the Arizona Geological Survey’s ability to serve the citizens of Arizona.  I urge those who will ultimately determine the fate of the Arizona Geological Survey to find a way for it to continue the important work it has done for the citizens of Arizona.

The details of the transfer are being worked out by officials in the Governor's office and the University. Some of the plan may be revealed with the fiscal year 2017 budget bills are released, which is expected in the next few weeks.

Arizona natural hazards viewer is AGI Map of the Day

The interactive map of natural hazards in Arizona produced by AZGS, was highlighted by the American Geosciences Institute as the Map of the Day on the AGI Critical Issues website. 

AZGS interactive map of natural hazards includes:

• Earthquakes since 1852
• Active faults and earth fissures
• Flood potential
• Fire risk index

The map is searchable by street address so that hazard information can be quickly and easily found for specific locations. Links are available for further information and mitigation tips, and all of the data can be downloaded for further use and analysis.

We are developing a statewide inventory of landslides, with over 4,500 compiled so far, which will be added as another layer to the map soon.

AGI says the Critical Issues Program provides a portal to decision-relevant, impartial, expert information from across the geosciences. The website aggregates material from a wide array of geoscience information providers in one place.

UA HiRISE camera - 10 years of amazing Mars photos

The Mars Reconnaissance Orbiter marked 10 years of circling the Red Planet earlier this month, sending back a continuing stream of amazing photos from the HiRISE camera managed by the University of Arizona.   Phil Plait, who blogs at Bad Astronomy, posted a wonderful retrospective of spectacular HiRISE images, including some I had not seen before.  The one below shows an avalanche cloud caught live in 2010 [Credit, NASA/JPL-Caltech/University of Arizona]

National landslides hazards bill introduced in US House

AZGS has been working with our colleagues to help craft the National Landslides Hazards Reduction Act which was introduced in the US House by Rep. Suzan DelBene  of Washington.  Rep. DelBene's district includes the Oso landslide which killed 42 people just two years ago.  

HR4776 includes provisions for a federal-state cooperative effort to conduct landslide hazards inventories and assessments in each state with federal matching funds.

AZGS also worked to include a section on creating a national landslide inventory database.    [Right, the highway 89A Bitter Springs landslide southwest of Page, AZ]