Can earthquakes from injected wastewater be predicted?

ASU scientist receives a grant to find out how much injected wastewater it takes to make an earthquake


August 23, 2018

One of the fastest-growing techniques for producing oil and gas today involves widening cracks in hydrocarbon-bearing rock formations underground. The cracks are opened by forcing a mixture of water, sand and chemicals into them in a process commonly called fracking.

The resulting fluid is processed to remove the oil and gas it has freed from the rock, and a wastewater residue called brine is left. The brine, which is toxic, is then disposed of by injecting it into deep layers of the Earth capped with rocks that keep it from reaching the surface. A house in central Oklahoma was damaged by the magnitude 5.6 earthquake on Nov. 6, 2011, which research suggests was caused by wastewater injected into deep disposal wells. ASU scientist Manoochehr Shirzaei has received a Department of Energy grant to develop a method for predicting the size and time of earthquakes from wastewater injection. Photo by Brian Sherrod/US Geological Survey Download Full Image

But the injection process, which is carried out far away from the fracking sites, can induce earthquakes. These may be large enough to damage buildings and other structures at the surface where the brine injection is done.

To gain an understanding of how brine injection causes earthquakes, Arizona State University scientist Manoochehr Shirzaei has received a $1 million grant (over three years) from the U.S. Department of Energy to model the injection process and its subsequent effects.

"Our goal is to find a physics-driven mathematical relationship between the amount of brine injected, its depth, and any effects at the surface," said Shirzaei, an assistant professor in ASU's School of Earth and Space Exploration.

"These effects can include earthquakes and also deformation — uplift — of the ground surface," he said.

First focus: Oklahoma

Initially the study will focus on Oklahoma, a state that has been a center for brine injection activities and which has logged a detailed record of seismic events. These include a magnitude 5.8 earthquake in September 2016.

"We will also consider expanding the research to include brine injection sites in Texas, California, Ohio, Kansas, and Colorado," Shirzaei said.

Seismic records are readily accessible for the study from the U.S. Geological Survey, and quantities of injected brines are, by law, made publically available by the companies involved.

A third element in the modeling is to include any deformation of the ground level. This is usually hard to measure because the effects are small and spread over a wide area. However, the use of interferometric synthetic-aperture radar (InSAR) data from orbit allows precise measurement of millimeter-scale uplifts over areas that are miles across.

Shirzaei explains, "We are looking to correlate injected wastewater quantities, measured deformation, and previous seismic activity to develop a model that can predict the likely effects of brine injection activity in a given area."

Because extraction of oil and gas is so important to a modern economy, Shirzaei expects the study will benefit a variety of stakeholders.

"The general public is the most important because they may be exposed to potential injury and damage," he said. The list also includes oil and gas producers, brine injection companies and geothermal energy providers.

"In addition, we expect the study will benefit land-management, regulatory, and permitting agencies," Shirzaei said. "Plus emergency managers and responders, building owners, insurers, mortgage holders and research scientists."

Robert Burnham

Science writer, School of Earth and Space Exploration

480-458-8207

 
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More than a label: Shelter dog genotyping reveals inaccuracy of breed assignments

Who are shelter dogs? ASU researchers collect DNA from over 900 dogs for study.
ASU study finds most shelter dogs are comprised of three different breeds.
Shelter dog breed identification is often inaccurate, ASU researchers say.
August 23, 2018

Genetic diversity in shelter dogs offers a new perspective on the implications of breed labels, ASU study finds

Editor's note: This story is being highlighted in ASU Now's year in review. Read more top stories from 2018 here.

Imagine meeting a potential roommate for coffee but instead of questions that gauge how compatible you both would be living together, you were asked about the ancestry of your parents’ families. Though this situation seems ridiculous, it happens all the time in animal shelters where dogs are assigned breeds that are often just guessed from their physical appearance. These breed assignments are then used to infer how the dogs might behave and also often impact the length of time a dog waits to be adopted.

The first step to understanding how breed labels might affect shelter dogs is to identify who shelter dogs actually are, and researchers in the Arizona State University Department of Psychology have done just that. The ASU scientists genotyped shelter dogs in Arizona and California and compared the genetic information to the breed labels assigned in shelters. The findings were published Aug. 23 in PLOS ONE.

Canine cheek swabs

Who are shelter dogs? To answer this question, ASU’s Canine Science Collaboratory researchers Lisa Gunter and Clive Wynne collected DNA from over 900 shelter dogs housed at the Arizona Animal Welfare League and Society for the Prevention of Cruelty to Animals (AAWL) in Phoenix and the San Diego Humane Society and Society for the Prevention of Cruelty to Animals (SDHS) in San Diego.

For the genetic testing, the researchers used the Wisdom Panel Canine DNA Test from Mars Veterinary, which is a commercially available product. A small brush was used to collect cells from the dogs' cheeks and gums, and the samples were sent to a lab for processing. At the lab, DNA was extracted from the dogs' cells and compared to over 300 sites in the canine genome that have been matched to specific breeds.

The three most common breeds at both the AAWL and SDHS were the same: American Staffordshire terrier, Chihuahua and poodle. Yet these three breeds accounted for less than half of the dogs in the two shelters.

“The level of genetic diversity in the shelter dogs exceeded our expectations: We found 125 distinct breeds,” said Gunter, who is a Maddie’s Research Fellow in the ASU Department of Psychology. “We also found that just 5 percent of the shelter dogs were purebred, even though it is commonly assumed that up to a quarter of dogs in shelters are purebred.”

The genetic testing gave the researchers information about three generations of ancestors for each dog. On average, most dogs were comprised of three different breeds, with some dogs having up to five breed signatures identified at the great-grandparent level.

“Breed identification has quite an outsize role in people’s perceptions of dogs,” said Wynne, professor of psychology and head of the Canine Science Collaboratory. “‘What breed is he?’ is often the first question people ask about a dog, but the answer is often terribly inaccurate.”

"When you adopt a dog, you are not adopting a bully, a German shepherd or Saint Bernard, you are adopting Jerry or Mo. When you love a dog, you don’t love a German shepherd. You love Jerry."
— Michael Morefield, director of marketing and communications for the AAWL

The accuracy and unintended consequences of a label

The genetic diversity among shelter dogs can make it difficult for shelter staff to assess the breed heritage of dogs. Gunter and Wynne partnered with ASU’s Rebecca Barber, assistant clinical professor in the Mary Lou Fulton Teachers College, to compare the breed information from the genetic testing to the labels given to the dogs in the San Diego shelter. At the SDHS, shelter staff used the physical appearance of a dog and breed descriptions from the American Kennel Club Breed Identification Guides to identify a primary and secondary breed.

When the researchers looked at whether either the assigned primary or secondary breed matched the information from the genetic profile of a dog, they found the shelter staff accuracy was 67 percent. The accuracy fell to 10 percent when staff identified more than one breed.

Though breed labels are common in animal shelters, they can have unintended consequences. In a previous study also published in PLOS ONE, the researchers found that dogs labeled as pit bulls waited over three times as long to be adopted. In this study, the researchers found that dogs in the San Diego shelter with a pit bull-type ancestry waited more than three times as long as other dog breeds.

How a breed label impacts a shelter dog extends beyond identification. The relationship between behavior and breed is murky except for certain behaviors that are breed-specific, like pointing.

“The genetics of behavior is so complex that a dog who is a cross of two breeds might not behave much like the typical members of either of its parents’ families,” Wynne said. “Then you have a situation where breed-typing is worse than stereotyping members of our own species. Breed labels would be better dropped altogether.”

Beyond breed labels to behavior

The behavioral diversity even within single breeds has led Gunter and Wynne to advocate for the importance of behavioral assessments instead of breed labels. What really matters is a dog’s behavior and how it might fit into an adoptive family, Gunter said.

“Shelter dogs are interesting and complex genetically,” Gunter said. “They really are individuals, and labeling them with a single breed can minimize their uniqueness.”

An important goal of the Canine Science Collaboratory is to design and validate a behavioral assessment that would provide insight into how dog behavior in a shelter translates to behavior in a home. Such an assessment would be more informative than breed labels and might positively impact shelter dogs.

The AAWL in Phoenix recently stopped publicizing breed information on their website and on kennel cards, though the breed labels are available upon request. The shelter, which has a long-standing relationship with the collaboratory, made the decision based on the findings from the previous study that showed how certain breed labels increased the length of stay in a shelter.

“Everything about the life experience of a dog — where he was before coming to the shelter or any medical issues he might have — is what makes him who he is, not who his grandparents might have been,” said Michael Morefield, director of marketing and communications for the AAWL. “When you adopt a dog, you are not adopting a bully, a German shepherd or Saint Bernard, you are adopting Jerry or Mo. When you love a dog, you don’t love a German shepherd. You love Jerry.”

Top photo courtesy Justin Veenema on Unsplash

Science writer , Psychology Department

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