The US Geological Survey has just published Field-trip guides to selected volcanoes and volcanic landscapes of the western United States Scientific Investigations Report 2017-5022. Links to separate chapters are found at https://pubs.er.usgs.gov/publication/sir20175022
The North American Cordillera is home to a greater diversity of volcanic provinces than any comparably sized region in the world. The interplay between changing plate-margin interactions, tectonic complexity, intra-crustal magma differentiation, and mantle melting have resulted in a wealth of volcanic landscapes. Field trips in this guide book collection (published as USGS Scientific Investigations Report 2017–5022) visit many of these landscapes, including (1) active subduction-related arc volcanoes in the Cascade Range; (2) flood basalts of the Columbia Plateau; (3) bimodal volcanism of the Snake River Plain-Yellowstone volcanic system; (4) some of the world’s largest known ignimbrites from southern Utah, central Colorado, and northern Nevada; (5) extension-related volcanism in the Rio Grande Rift and Basin and Range Province; and (6) the eastern Sierra Nevada featuring Long Valley Caldera and the iconic Bishop Tuff. Some of the field trips focus on volcanic eruptive and emplacement processes, calling attention to the fact that the western United States provides opportunities to examine a wide range of volcanological phenomena at many scales.
The 2017 Scientific Assembly of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) in Portland, Oregon, was the impetus to update field guides for many of the volcanoes in the Cascades Arc, as well as publish new guides for numerous volcanic provinces and features of the North American Cordillera. This collection of guidebooks summarizes decades of advances in understanding of magmatic and tectonic processes of volcanic western North America.
These field guides are intended for future generations of scientists and the general public as introductions to these fascinating areas; the hope is that the general public will be enticed toward further exploration and that scientists will pursue further field-based research.
The U.S. Geological Survey has just published a new assessment of mineral resources vital to our modern economy: Critical mineral resources of the United States—Economic and environmental geology and prospects for future supply, Professional Paper 1802
Edited by:Klaus J. Schulz , John H. DeYoung Jr. , Robert R. Seal II , and Dwight C. Bradley
You can download the entire book (148 Mb) and/or individual chapters here:
The book consists of two introductory chapters and 20 chapters which each discuss the geology, mineralogy, and occurrence of specific mineral commodities. Note that the U.S. is entirely dependent on imports for 20 critical minerals (see page 6 of this publication for a chart:https://minerals.usgs.gov/minerals/pubs/mcs/2017/mcs2017.pdf )
The following map from PP1802 shows where the U.S. gets minerals for which we are at least 50 percent dependent on imports.
The first chapter in PP1802 justifies the need for this report as follows:
The global demand for mineral commodities is at an all time high and is expected to continue to increase, and the development of new technologies and products has led to the use of a greater number of mineral commodities in increasing quantities to the point that, today, essentially all naturally occurring elements have several significant industrial uses. Although most mineral commodities are present in sufficient amounts in the earth to provide adequate supplies for many years to come, their availability can be affected by such factors as social constraints, politics, laws, environmental regulations, land-use restrictions, economics, and infrastructure.
This volume presents updated reviews of 23 mineral commodities and commodity groups viewed as critical to a broad range of existing and emerging technologies, renewable energy, and national security. The commodities or commodity groups included are antimony, barite, beryllium, cobalt, fluorine, gallium, germanium, graphite, hafnium, indium, lithium, manganese, niobium, platinum-group elements, rare-earth elements, rhenium, selenium, tantalum, tellurium, tin, titanium, vanadium, and zirconium. All these commodities have been listed as critical and (or) strategic in one or more of the recent studies based on assessed likelihood of supply interruption and the possible cost of such a disruption to the assessor. For some of the minerals, current production is limited to only one or a few countries. For many, the United States currently has no mine production or any significant identified resources and is largely dependent on imports to meet its needs. As a result, the emphasis in this volume is on the global distribution and availability of each mineral commodity. The environmental issues related to production of each mineral commodity, including current mitigation and remediation approaches to deal with these challenges, are also addressed.
This article notes: The value of all non-fuel minerals produced from U.S. mines was $74.6 billion, a slight increase over production in 2015. “ Domestic raw materials and domestically recycled materials were used to process mineral materials worth $675 billion. These mineral materials were, in turn, consumed by downstream industries with an estimated value of $2.78 trillion in 2016.” Nevada was ranked first with a total mineral production value of $7.65 billion, mainly from gold. Arizona came in second in total production with a value of $5.56 billion and first in U.S. copper production.
The herbicide glyphosate is the main ingredient in Monsanto’s Roundup weed killer. This product has been used for more than 40 years on farms, residential lawns, and on golf courses. Environmentalists have been conducting a scaremongering campaign asking for a world-wide ban.
Glyphosate was classified as a probable human carcinogen by the World Health Organization (WHO) in March 2015, based on very sketchy evidence. However, in November 2015, the European Food Safety Authority determined that glyphosate was unlikely to pose a carcinogenic hazard to humans. In May 2016, the Joint Food and Agriculture Organization meeting on pesticide residues (another subdivision of the WHO), concluded that glyphosate was unlikely to pose a carcinogenic risk to humans from exposure through the diet.
A new study published December 12, 2017 by the Environmental Protection Agency concludes that glyphosate and its metabolites are not likely to be harmful to humans, neither as a carcinogen, nor harmful in other ways. You can read the entire 216-page report here.
The EPA reviewed thousands of studies relating to glyphosate effects on humans and other animals. The EPA’s main conclusion: “In summary, considering the entire range of information for the weight-of-evidence, the evidence outlined above to potentially support the ‘suggestive evidence of carcinogenic potential’ descriptor are contradicted by other studies of equal or higher quality and, therefore, the data do not support this cancer classification descriptor.” The strongest support is for “not likely to be carcinogenic to humans.”
This story has been largely ignored by the mainstream media. I did find mention by Reuters which noted that the EPA reported that glyphosate is not likely to be carcinogenic to humans and found “no other meaningful risks to human health” when glyphosate, the world’s biggest-selling weed killer, is used according to its label instructions.
There was also mention in the LATimes which pointed out that the EPA finding contradicted “California regulators, who have included the chemical on the Proposition 65 list of probable carcinogens.”
As Steve Milloy pointed out in a June 19, 2017, Washington Times article, it’s time to dismantle the chemical scaremongering industry.
For additional background see Is glyphosate, used with some GM crops, dangerously toxic to humans? From the Genetic Literacy Project (link). They point out:
Toxicity is all about dosage; this applies to all substances. Some chemicals like aflatoxin and botulin are toxic in small doses, while others like vitamin D and caffeine have low toxicity, becoming dangerous only at higher doses.
Let’s take a closer look at glyphosate. Glyphosate is derived from an amino acid, glycine. It acts against plants by suppressing an essential biochemical mechanism commonly found in plants, but not in animals. According to the Extension Toxicology Network, a joint pesticide information project by Cornell University, Michigan State University, Oregon State University and University of California at Davis, and funded by US Department of Agriculture, glyphosate is non-volatile, minimizing exposure through inhalation, and undergoes little metabolism in the human body. If accidentally consumed, glyphosate is excreted mostly unchanged in feces and urine, so it doesn’t stay in the body and accumulate.
The EPA has also determined that glyphosate has “minimal” ecological effects. Glyphosate is only slightly toxic to birds and fish, and it binds tightly to the soil, reducing the possibilities of leaching. Microbes in the soil then break glyphosate down so it doesn’t accumulate in the soil. According to plant pathologist Steve Savage, glyphosate has also replaced mechanical tillage to destroy weeds, which is “a substantial positive for the environment because of reduced erosion and retention of soil carbon.”
So how toxic is glyphosate exactly? To examine toxicity, one must look at the LD50 value given to the chemical in question. LD50 is a standard measure of acute toxicity for chemicals, expressed in the amount of chemical (milligrams) per body weight (kg) that it took to kill fifty percent of a population of test animals. Because LD50 is a standard measure, it is used to compare toxicities of compounds; the lower the number, the more toxic it is.
Glyphosate has a LD50 of 5600 mg/kg based on oral ingestions in rats, according to EPA assessments (PDF), placing it in Toxicity Category III. The EPA ranks chemicals in four categories, I being the most toxic and IV being the least. The EPA has also found that glyphosate does not cause cancer. To compare, caffeine has a much lower LD50 of 192 mg/kg based on oral ingestions in rats.
These words are followed by a chart of LD50 for many common substances.
Phil Anderson (Ph.D., University of Arizona) had a genius for mapping and interpreting the Proterozoic geology, tectonics, and mineral deposits of the Southwest. Unfortunately, his mapping was never made public, until now.
From the mid-1970s to the early 1990s, Phil traversed Arizona’s Transition Zone visiting and studying nearly every exposure of Proterozoic rocks. He described this work in his 1986 dissertation, ‘The Proterozoic tectonic evolution of Arizona’, and two subsequent papers from the Arizona Geological Society’s Digest 17, but he did not disclose his geologic maps. He issued, instead, small-scale, state-wide overviews of the distribution of Proterozoic rocks.
Phil passed away in Payson, Arizona, in Feb. 2012. In Sept. 2017, Donna Smart, Phil’s widow, donated Phil’s geologic map products and files – his life’s work – to the Arizona Geological Survey. Steve Reynolds (ASU Earth and Space Science Exploration) then organized and led a team of geoscientists in salvaging, reviewing, and selecting Anderson’s geologic maps to release as ‘The Philip Anderson Arizona Proterozoic Archive.‘
Reynolds & others (2017) contextualizing Anderson’s contribution to the Proterozoic of Arizona;
11 geologic topographic quadrangles (1:24,000) from central Arizona’s Bradshaw Mountains, with key and legend;
A suite of geologic, structural, and tectonic illustrations;
9 sub-regional geochemical plots;
2 papers (totaling 150 p.) authored by Phil Anderson and published in the Arizona Geological Society’s Digest 17.
This is the first of a suite of Anderson geologic map products that we plan to release. The remaining Anderson collection comprises dozens of other topographic maps with original geologic observations and notes regarding structures and mineralogy. It will take several hundred hours to review, process, and prepare these materials for release.
In the meantime, researchers working in the Proterozoic of Arizona’s Transition Zone are advised to reach out to the AZGS with specific requests for information.
Acknowledgments. We thank Donna Smart for preserving and donating Phil Anderson’s geologic research. We thank, too, David Briggs (President) and the Arizona Geological Society Executive Committee for their generous permission to include Phil’s two papers from AGS Digest 17.
Anderson, Phillip, 1986, The Proterozoic tectonic evolution of Arizona; Tucson, University of Arizona, unpublished PhD dissertation, 416 pages.
Anderson, Phillip, 1989a, Proterozoic plate tectonic evolution of Arizona, in Jenney, J.P., and Reynolds, S.J., 1989, Geologic evolution of Arizona: Tucson, Arizona Geological Society Digest 17, p. 17 – 55.
Anderson, Phillip, 1989b, Stratigraphic framework, volcanic plutonic evolution, and vertical deformation of the Proterozoic volcanic belts of central Arizona, in Jenney, J.P., and Reynolds, S.J., 1989, Geologic evolution of Arizona: Tucson, Arizona Geological Society Digest 17, p. 57 -147.
Reynolds, S.J, Conway, F.M., Johnson, J.K., Doe, M.F., Niemuth, N.J., 2017, The Phillip Anderson Arizona Proterozoic Archive. Arizona Geological Survey Contributed Report CR-17-D, 2 p.
This issue begins with several articles on the often adversarial relationship between property rights, the Endangered Species Act, and conservation.
The Endangered Species Act (ESA) should be repealed because it provides no positive incentive for conservation, it tramples on property rights, it destroys industries, it is very expensive, and it is ineffective. The ESA should be replaced with a voluntary, non-regulatory, incentive-based act. Make conservation profitable. The fundamental political problem with the act is that its incentives don’t match its ethics. Conserving endangered species benefits everyone in society, but a small number of people bear the cost , usually the landowners whose property use could be restricted if a protected species turns up.
We also look at the “Core of climate change is in the real-world data” and show that carbon dioxide is definitely not a principal driver.
Finally, we look at Rights vs Benefits – What’s the difference.
The Gila Topminnow was once ubiquitous within the Gila River drainage, but its population declined due to introduction of non-native species, water impoundment and diversion, water pollution, groundwater pumping, stream channelization, and habitat modification. It was listed as an endangered species in March of 1967. This guppy-like, live-bearing fish is 1-2 inches long. Breeding males are jet black with yellow fins. Gila topminnow are omnivorous, and eat food such as detritus and crustaceans; but feed mostly on aquatic insect larvae, especially mosquitos.
According to a press release by the US Fish&Wildlife Service (FWS) et al., During a November survey, Gila Topminnows were rediscovered within the Santa Cruz River north of Tucson just downstream of the water treatment plants after a 70-year absence. Topminnows were also found in the Santa Cruz River just north of the sewer treatment plant in Nogales, Arizona, in December 2015.
Here is the lede from the press release:
After an absence of more than 70 years, the endangered Gila topminnow has reappeared in the Santa Cruz River in northwest Tucson, fish surveys conducted in November confirm.
Scientists were hopeful native fish would return to the river near Tucson after the river’s water quality significantly improved following upgrades to wastewater treatment facilities releasing effluent (highly treated wastewater) into the river at Agua Nueva and Tres Rios treatment plants in 2013. The native Arizona species, listed under the Endangered Species Act, was rediscovered in the Santa Cruz River near Nogales, Arizona in 2015. Both sections of the river where the fish reappeared depend on releases of effluent, demonstrating the critical role this water plays for the river’s health.
More from the press release: “Finding Gila Topminnow in the Santa Cruz River in Tucson is the most significant conservation discovery since the species was listed as endangered in 1967,” said Doug Duncan, fish biologist with the U.S. Fish and Wildlife Service. “We are not certain how the fish made it to the Tucson reach of the river, but we will analyze the genetics of the fish and river flow data to see if we can make that determination.”
How did the fish get into the Santa Cruz River? In my opinion, captive-bred fish were put into the river or they escaped from nearby mosquito-control projects. It is also possible that the heavy rains we had in July washed some into the current location.
Pima will have a new ally in the battle against mosquito-borne diseases this summer: endangered Gila topminnow.
The Arizona Game and Fish Department (AZGFD) provided 500 of the native fish, which will be introduced into standing waters in urban county areas. The project is being done under the Department’s federal permits and an Endangered Species Act Habitat Conservation Plan between Pima County and the U.S. Fish and Wildlife Service. The three agencies are cooperatively spearheading this effort to reduce threats to public health in the county. The project is part of an overall plan by Pima County Health Department, Pima County Sustainability and Conservation, the Phoenix Zoo and Arizona State University to use the federally endangered fish to target mosquito larvae and reduce the threat of mosquito-borne diseases, such as the West Nile and Zika viruses. This approach is also being considered for future deployment in Pinal County and hopefully other county governments around the state.
Also from FWS: “The species is currently being reared at over 100 locations for reestablishment into numerous sites in Arizona. The Gila topminnow has been released at almost 200 locations in efforts to reestablish populations.”
“The University of Arizona has been ordered to surrender emails by two UA scientists that a group claims will help prove that theories about human-caused climate change are false and part of a conspiracy.” (Arizona Daily Star) The professors involved are Malcolm Hughes, who is still with the UA, and Jonathan Overpeck, who left earlier this year.
The backstory begins in 2009:
In 2009, it was revealed that someone hacked in to the files of the Climatic Research Unit (CRU) based at the University of East Anglia, in England. The CRU has been a major proponent of anthropogenic global warming and a principal in report preparation for the Intergovernmental Panel on Climate Change (IPCC).
More than 1,000 internal emails and several reports from CRU have been posted on the internet and the blogosphere had gone wild with the implications of the revealed messages. Dr. Phil Jones, head of CRU, confirmed that his organization has been hacked and that the emails are accurate. This disclosure did not include any Emails at other institutions such as Penn State or the University of Arizona.
The emails reveal a concerted effort on the part of a small group of scientists to manipulate data, suppress dissent, and foil the dissemination of the information by “losing” data and skirting Britain’s Freedom of Information Act. The emails reveal that the contention of dangerous human-induced global warming is not supported by the data, that those supporting that contention knew it, and sought to control the discussion so as to hide the unreliable nature of what they were claiming.
Part of the controversy involved the infamous “hock stick” graph devised by Michael Mann of Penn State and subsequently adopted by the IPCC.
In the “battle of the graphs” the bottom panel shows temperatures based on proxy data and measurements. It shows that the Medieval Warm Period of 1,000 years ago was much warmer than now. Mann’s hockey stick did away with the Medieval Warm Period and showed only a large spike of recent warming – hence the name “hockey stick”. The “hockey stick” made its debut in the journal Geophysical Research Letters in 1999 in a paper by Michael Mann, Raymond Bradley, and Malcolm Hughes that built upon a 1998 paper by the same authors in the journal Nature which detailed the methodology for creating a proxy temperature reconstruction.
There are problems with the Hockey Stick according to Canadian researchers Steve McIntyre and Ross McKitrick. “The first mistake made by Mann et al. and copied by the UN in 2001 lay in the choice of proxy data. The UN’s 1996 report had recommended against reliance upon bristlecone pines as proxies for reconstructing temperature because 20th-century carbon-dioxide fertilization accelerated annual growth and caused a false appearance of exceptional recent warming. Notwithstanding the warning against reliance upon bristlecones in UN 1996, Mann et al. had relied chiefly upon a series of bristlecone-pine datasets for their reconstruction of medieval temperatures. Worse, their statistical model had given the bristlecone-pine data sets 390 times more prominence than the other datasets they had used.
Furthermore, the statistical algorithms in Mann et al. where shown to be flawed. McIntyre ran the Mann’s algorithm 10,000 times, having replaced all palaeoclimatological data with randomly-generated, electronic “red noise”. They found that, even with this entirely random data, altogether unconnected with the temperature record, the model nearly always constructed a “hockey stick” curve similar to that in the UN’s 2001 report.” (See their detailed report)
Mann had another problem. Their proxy data began to rise, but then took a plunge into cooler temperatures. They hid this decline by truncating the proxy data and substituting rising measured temperatures without telling anyone. This became known as “Mike’s Nature Trick”. (Read more)
One other incident: In my article A Simple Question for Climate Alarmists I posed this question: “What physical evidence supports the contention that carbon dioxide emissions from burning fossil fuels are the principal cause of global warming since 1970?” In a public forum, I had the opportunity to pose this question to then UofA professor Jonathan Overpeck. He could not cite any supporting physical evidence.
There has been much controversy over President Trump’s proposed budget and the revision of health care. Much of the proposed spending in Trump’s budget and previous budgets is not supported by the Constitution.
The 2016 federal budget, submitted by Barack Obama, was $4.147 trillion which was 21.5% of GDP and resulted in a deficit for the year of $503 billion. The total federal deficit is almost $20 trillion. Although the President submits or suggests budgets, it is the duty of Congress to appropriate the money. In my opinion, a large part of federal spending is unconstitutional.
The Constitution of the United States grants certain powers to Congress and Executive Branch. Over the years, Congress has greatly exceeded its Constitutional authority. Federal agencies have created thousands of regulations and spent trillions of dollars of taxpayers’ money on things for which they had no authority to do so. These regulations have the force of law, but only Congress can make law. There is a movement to change the constitution with a balanced budget amendment. Such an amendment would be unnecessary if only Congress and the President would enforce the Constitution.
Below are the Constitutionally enumerated powers of Congress. Nowhere in this enumeration can I find the authority for the federal government to have Departments of Education, Labor, or Energy. I see no authority for the Environmental Protection Agency, nor the requirement that citizens buy health insurance. Some may also argue that our whole welfare and medical care systems are unconstitutional. And, as Benjamin Franklin once said, “I am for doing good to the poor, but I differ in opinion of the means. I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it.”
The principal authority of Congress is specified in Article I of the Constitution.
Article I, Section 8 :The powers of Congress:
The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States;
To borrow Money on the credit of the United States;
To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes;
To establish an uniform Rule of Naturalization, and uniform Laws on the subject of Bankruptcies throughout the United States;
To coin Money, regulate the Value thereof, and of foreign Coin, and fix the Standard of Weights and Measures;
To provide for the Punishment of counterfeiting the Securities and current Coin of the United States;
To establish Post Offices and post Roads;
To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;
To constitute Tribunals inferior to the supreme Court;
To define and punish Piracies and Felonies committed on the high Seas, and Offences against the Law of Nations;
To declare War, grant Letters of Marque and Reprisal, and make Rules concerning Captures on Land and Water;
To raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years;
To provide and maintain a Navy;
To make Rules for the Government and Regulation of the land and naval Forces;
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress;
To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the Acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings; — And
To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.
Other Authority granted to Congress by the Constitution:
Article IV, Section 3, clause 2: “The Congress shall have Power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States; and nothing in this Constitution shall be so construed as to Prejudice any Claims of the United States, or of any particular State.”
The 16th Amendment: “The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration.”
See any justification for Departments of Education, Labor, Energy, or Environmental Protection Agency etc. there? Of course, strictly speaking, there is no justification for Social Security or Medicare either. “If Congress can do whatever in their discretion can be done by money, and will promote the General Welfare, the Government is no longer a limited one, possessing enumerated powers, but an indefinite one, subject to particular exceptions.” —James Madison (1792)
The 10th Amendment also limits the powers of Congress: “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.”
The Heritage Foundation opines: Those who claim the Department of Education is Constitutional say that it promotes the general welfare of the United States, however, this phrase in the preamble of the Constitution does not grant or prohibit power to Congress, that is not its purpose. The preamble simply describes the Constitution and what the document itself was designed to do, and is not actually a binding decree of the Constitution.
The Department of Education was founded using the preamble as the basis for its Constitutionality, but due to what’s stated above, it is clear that it is not. Thomas Jefferson considered the federal government’s involvement in education to be unconstitutional. In 1862, James Buchanan warned that giving education to Congress would create a vast and irresponsible authority. Both he and Jefferson were right. (Source)
Another type of unconstitutional spending occurs when agencies make unauthorized payments. Article I, Section 9 of the Constitution says in part: “No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law; and a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time.” That provision was invoked in a lawsuit House of Representatives v. Burwell, which involved reimbursements the Department of Health and Human Services (HHS) had been paying to insurers to keep out-of-pocket costs artificially low for patients with incomes up to 250 percent of the federal poverty line. Congress refused to appropriate the funds for this scheme, but HHS reimbursed the insurers anyway, whereupon the House sued the Obama administration. The judge ruled that the payment of such reimbursements without congressional authorization “violates the Constitution.” (Source)
The essential idea of the Constitution is that the federal government has limited powers, as stated in the 10th Amendment. It’s time to return to the original meaning of the Constitution and downsize the federal government where it is politically possible to do so. Let each State decide how to handle its own business. States might be more circumspect and accountable to their citizens than is a far-off federal government. (Or, they might become California.)
I’m sure you can think of other instances where the federal government is spending taxpayer money on things not authorized by the Constitution.
Geoscientists agree, there is no such thing as an earthquake season. The tectonic forces producing earthquakes are inured from changes in meteorological or astronomical conditions; the latter involves fluctuation in gravitational forces due to the position of Earth’s Moon.
Arizona does, however, have an earth fissure season. A season when earth fissures are more likely to first appear or undergo renewed activity. Central and southeastern Arizona’s earth fissure season accompanies the onset of torrential rainfall of the summer monsoon, from mid-June to late September, with most precipitation occurring from mid-July to mid-August.
In southern and western Arizona, Cochise, La Paz, Maricopa, Pima and Pinal Counties all host earth fissures. In these five counties, we‘ve identified nearly 30 discrete earth fissure study areas, each with its own history, and comprising a collective 170 miles of mapped fissures and an additional 180 miles of reported but unconfirmed fissures. (Why unconfirmed? Three principal reasons: 1) ground disturbance has effectively masked the fissure; 2) built infrastructure now covers the fissure; 3) the feature was incorrectly identified as a fissure initially.)
Release of 4 revised earth fissure maps
Each monsoon season finds the AZGS’ mapping team in the field addressing new leads and revisiting fissures with a history of activity. Mapping results are compiled on existing earth fissure study area maps, which are then revised, re-versioned, and released online at the interactive Natural Hazards in Arizona site. At the same time, we release an updated ESRI spatial data file (.shp) and Google Earth KMZ file, ‘Locations of Mapped Earth Fissure Traces in Arizona’, versioned to the date of release, in this case 06 Nov. 2017.
This year we are releasing revised maps for four earth fissure study areas (Figure 1):
Two of these, Apache Junction and Chandler Heights, have largely shifted from agricultural lands to residential or industrial use lands, markedly increasing the hazard and risk that accompanies fissuring.
Fissure activity ranges widely within and between study areas. Not all fissures are created equal; and not all fissures display activity each monsoon season. Most study areas retain some active fissures that either display slow incremental expansion, or dramatic episodic growth powered by eroding sheet flow accompanying torrential rains; sheet flow fans across the valley surface as a thin sheet of water spilling into open fissures eroding sidewalls and causing gullying.
Existing fissures frequently capture numerous drainages leading to incision (headcutting) on the up-channel side. Fissures often form orthogonal to the natural drainage direction, so channels and washes intersected by the fissure deliver water during and after rains.
With reduced groundwater harvesting and waning subsidence, fissures may transition from active to inactive status. When this occurs, they become sediment traps for wind- and water-borne sediments – clays, silts and sands – that subsume the fissure, masking its diagnostic morphology – a wide open throat, steep to inclined sidewalls and a hummocky, irregular base. Reactivation of dormant, partially filled earth fissures, may occur if heavy runoff, coupled with even modest land subsidence that produces tensional forces sufficient to reopen the fissure, counters the ‘healing’ process, leading to a wider and more deeply incised fissure.
Apache Junction: Case Study of a Reactivated Fissure
The Apache Junction earth fissure study area map was first released in April 2008. Over the past several years AZGS Earth Fissure manager Joe Cook has revisited the Apache Junction virtually, via Google Earth, and physically to examine new or reactivated earth fissures. According to Cook, ‘there’s about 0.8 miles of new fissures in Apache Junction since April 2008. Many of the new fissures formed parallel to existing fissures or connected gaps in formerly discontinuous fissures.’
On the morning of July 24, 2017, following heavy rains on the late evening and early morning hours of 23-24 July, nearly 320 feet of fresh fissure opened near West Houston Ave., Apache Junction (Figure 2). This new feature is part of a larger fissure zone that stretches for more than 2 miles from near the junction of Baseline and Meridian Roads to south of West Guadalupe Road (Figure 2a). The fissure complex tunnels below streets, state trust land, private property, and large power lines.
According to Joe Cook’s report; ‘The fissure cracked West Houston Ave and an open void was visible beneath the road through a collapsed pothole. The road was closed to vehicle traffic immediately, but additional road collapse occurred over the days and weeks that followed. Large open depressions approximately 5-15 feet across and up to 8 feet deep, partially filled with collapsed material, were visible on private property to the south of Houston Ave. These open depressions were connected by parallel cracks beginning at Houston Ave to the north. Hairline cracks continued south of the southern-most depression for approximately 80 feet. Locally, a void space was visible below the hairline cracks indicating a strong potential for additional collapse.’
‘North of Houston Ave, the new fissure paralleled numerous, active and inactive, older fissures across the undeveloped desert floor. Additional reactivation and collapse along previously mapped fissures was observed beneath the powerlines in the southern part of the Apache Junction Study area.’
‘The cause for collapse of the fissure beneath Houston Ave is probably related to years of subsurface erosion along a buried earth fissure trace which intercepts rainwater from numerous drainages captured by the open portion of the fissure north of Houston Ave. During heavy rain events a substantial volume of floodwater is delivered to the fissure in a drainage ditch adjacent to the north side of W Houston Ave. Waning flow in this drainage ditch was observed to be pouring into the open fissure on the morning of July 25, 2017. No flow in the drainage ditch was observed downstream of the intersection with the earth fissure. The water draining into the fissure was not visible along the fissure anywhere else; water poured into the fissure in a free fall of about 8 feet before disappearing to unknown depths. Void space for further collapse must be substantial, which suggests that continued collapse following heavy rains is possible.’
By August 15, 2017 the collapsed portion of the fissure within the private property south of Houston Ave had been filled, presumably by the owner. But additional damage was evident, and the collapsed section of Houston Ave. remained closed.
Tator Hills: Case Study of a Fresh Fissure
Over the past several years, Tator Hills in southern Pinal County displayed the greatest fresh fissure activity of the four study areas (Figure 3). Imagery served by Google Earth shows that between Mar. 2014 and Dec. 2014, a mile-long, north-south trending earth fissure unzipped about 13 miles south of Arizona City. Sometime after March 2016, the fissure extended an additional ¾ mile to the south. The appearance of this fresh, 2-mile long fissure in an area of modest land subsidence ~ 1 inch (3 cm) annually over the past decade, and otherwise lacking active fissure formation since the early 1990s, was surprising (Cook, 2017).
Applying drone technology to fissures. In Jan. 2017, AZGS geoscientists captured a real-time synoptic view of the newest Tator Hills fissure using a DJI-PhantomTM Drone. AZGS research scientist Brian Gootee piloted the drone and captured videos at 2.7K horizontal resolution, as well as 100s of high resolution, 12 Mb static JPEG images. The latter were stitched together using AgiSoft PhotoScanTM software and analyzed using both AgiSoft PhotoScanTM and ESRI’s ArcGISTM.
At our AZGS Youtube channel, the Tator Hills fissure videos have been viewed an astounding 780,000 times! See Drone technology examining an earth fissure or Drone video of a fresh earth fissure, Tator Hills, Arizona.
The drone’s bird’s-eye view yielded a suite of derivative products – oblique orthoimagery, relief/slope map, digital elevation model (DEM), and topographic maps with contour interval of 1- to 2-feet (Figure 4) – that afford a fresh view of fissure geometry, structure, and topography that may yield new insights into the formative and evolutionary processes of fissures.
Chandler Heights and Three Sisters Buttes. Since release of earlier mapping, we documented subtle changes in some fissures at Chandler Heights (2016), Maricopa County, and Three Sisters Buttes (2012), Cochise County. Chandler Heights infamous ‘Y-Fissure’, so called because of its Y-shaped geometry, remains active but the dramatic reopening and lateral extension observed in previous years has not recurred over the past several years. Nonetheless, the ‘Y-Fissure’ remains of great interest, in part because it winds through neighborhoods in east Queen Creek.
Agriculture is the economic engine that drives Cochise County. The Three Sisters Buttes study area lies several miles southeast of Willcox Playa. Groundwater withdrawal and concurrent basin subsidence continues there unabated and from May 2010 to April 2017, maximum subsidence in the basin reached 9.8 – 15.7 in; 5 to 15 times greater than subsidence observed in the Tator Hills. In rural Cochise County, fissures chiefly threaten roads and pipelines and road signs warning of fissures is a common sight (Figure 5).
Some Observations & Final Thoughts
For the foreseeable future, earth fissures remain a geologic hazard in central and southeastern Arizona. With urban and suburban areas aggressively expanding into former agricultural areas, county and municipal planners may anticipate new and renewed incidents of costly and potentially hazardous impacts, as evinced by the recent damage to the W. Houston Rd. and nearby industrial plant in Apache Junction.
The state of earth fissures in Arizona. Nonetheless, there is hope on the horizon for a diminished threat from earth fissures. According to a recent blog post by hydrologist Brian Conway (Arizona Dept. of Water Resources), ‘Land subsidence rates within the Phoenix and Tucson Active Management Areas (AMAs) have decreased between 25% and 90% compared to the 1990s. This is a result of decreased groundwater pumping, increased groundwater recharge, and recovering groundwater levels in the two AMAs.’
Controlling groundwater pumping reduces basin subsidence, which should in turn re-establish hydrostatic equilibrium across impacted basins, thereby reducing the extensional stresses that lead to fissure formation.
Since 2007, systematic mapping of fissure study areas in Maricopa, Pima and Pinal Counties has uncovered few new earth fissures. Moreover, many fissures mapped between 2007 and 2009 showed physical evidence of having formed years or decades before. It could well be that the rate of earth fissure formation in most study areas reached its apex in the latter quarter of the 20th century. If so, land managers in these impacted areas should anticipate seeing fewer new fissures forming and, perhaps, waning reactivation of existing fissures.
In Cochise County, where groundwater pumping and basin subsidence continues unabated, we anticipate new fissures forming annually and existing fissures reopening.
Note of caution. There could be a substantial time-lag between reduced pumping, waning subsidence rates, and the end of new or renewed fissuring. By way of example, subsidence in the Tator Hills area has slowed substantially since the latter quarter of the 20th century. From 2004 to 2017, total subsidence proximal to the 2-mile long fissure was between 1.6 to 3.2 inches; a magnitude of subsidence that seems inconsistent with the formation of a 2-mile long fissure. This fissure may have formed years before, only to break the ground surface in 2014. This could be true of concealed fissures in other study areas, too. We strongly recommend that civil authorities, farmers, contractors, and the public remain on the alert for the sudden emergence of rogue, outlier fissures.
Final Thoughts. The AZGS fissure mapping team continues to monitor earth fissure study areas, both virtually, via Google Earth and fresh National Agriculture Imagery Program (NAIP) imagery, and physically by returning to study areas. We confer regularly with county and municipal authorities regarding reports of reactivated or new fissures. Last, we remain aware of the potential of fissures forming in areas where the imbalance between groundwater harvesting and recharge leads to measurable basin subsidence, such as in agricultural lands of Cochise County and the McMullen Valley of Maricopa and La Paz Counties.
Arizona Land Subsidence Group, 2007, Land Subsidence and Earth Fissures in Arizona: Research and Informational Needs for Effective Management: Arizona Geological Survey Contributed Report CR-07-C, 29 p.
Schumann, H.H., and Cripe, L.S. (1986). Land subsidence and earth fissures caused by groundwater depletion in Southern Arizona, U.S.A. In A.I. Johnson, L. Carbognin & L. Ubertini (Eds.], Proceedings of the 3rd International Symposium on Land Subsidence, Venice, Italy, 19-25 March 1984 (pp. 841-851). International Association of Hydrological Sciences, Publication 151.
If you drive Interstate 10 between Tucson and Phoenix, about half way you pass between the Picacho Mountains (on the northeast side) and Picacho Peak (on the southwest side). Picacho Peak State Park is a frequent destination for picnics, rock climbing, and viewing spring wildflowers.
The Arizona Geological Survey has recently made available for free download Geologic Field Guides to the Southeastern Picacho Mountains and Picacho Peak. (Link)
From the guide:
The Picacho Mountains consist largely of a compositionally diverse suite of Laramide to middle Tertiary biotite granite, muscovite granite, and heterogeneous to gneissic granite. At the southern end of the range, most of the crystalline rocks have been affected by middle Tertiary mylonitic deformation. Mylonitization is inferred to have accompanied normal faulting and ascent of the bedrock from mid-crustal depths to near the Earth’s surface. [Mylonitization is modification due to dynamic recrystallization following plastic flow.]
Ascent occurred in the footwall of a moderate to low-angle normal fault commonly known as a “detachment fault”. The crystalline rocks of the Picacho Mountains are part of the footwall of a south- to southwest-dipping detachment fault that is exposed only at the base of a small klippe of volcanic rock on a hill top in the southeastern Picacho Mountains. [A klippe is an isolated block of rock separated from the underlying rocks by a fault.]
Picacho Peak, itself, looks like the remnant of a volcano. However, it is an erosional remnant of volcanic rocks that were displaced from over the Picacho Mountains by a detachment fault.
Picacho Peak is composed of multiple andesitic lava flows interbedded with thin sequences of medium- to thin-bedded, well-sorted, medium- to coarse-grained arkosic sandstone and granule sandstone. See the guide for detailed descriptions.