>>Dr. Robert Puls: Today we have Austin Holland with us. Austin is a seismologist with the
Oklahoma Geological Survey. Welcome Austin.
>>Austin Holland: Thank you.
>>Dr. Puls: So Austin got his education, first his bachelor's degree at the University of
Idaho. He then did his masters work at the University of Texas El Paso and then he went
to work for twelve years at the Idaho National Engineering Lab. Since leaving there, he joined
the Oklahoma Geological Survey where he's been doing work on seismic activity in the
state of Oklahoma. So recently there's been a significant increase in seismic activity
in the state, and people are asking a lot of questions. I understand you're the one
that a lot of them are coming for-- coming to for answers. Can you give the students
some background on what the latest is in terms of the seismic activity and its uptick in
frequency?
>>Austin Holland: Sure, Oklahoma's always had earthquakes. We have had a seismic monitoring
network since the late 1970s, so we're well poised to look at this earthquake, earthquake
increase. So we've seen roughly 80 times more earthquakes than we have previously. That's
just a remarkable number. But in addition we've also had a number of additional seismic
stations in the state. Part of the National Science Foundation EarthScope Program was
moving this U. S. array of these seismic stations and translating them across the country, and
they're now on the east coast. But at the time when the earthquakes first started really
ticking up here in Oklahoma in late 2009, all these stations were in the state. So we
were able to learn and are learning a lot more about these earthquakes as they continue
to occur. So we're having roughly a hundred or more than a hundred felt earthquakes every
year, and we used to average about one to three, maybe five earth quakes a year that
would be felt by local residents.
>>Dr. Puls: So it was highly fortuitous than that the-- this array was where it was, when
it was there, in terms of having all these additional monitoring stations?
>>Austin Holland: Yes. And it is part of the reason they rushed to bring me into the Geological
Survey when they did, is we were down some staff and they had this need to bring in this,
this data and incorporate it into the regional network. And so we did that, and it was just
an amazing resource. And we're still-- I mean we have decades worth of science to be done
with this incredible data set.
>>Dr. Puls: So how, how easy is it to deploy these these meters to detect this activity?
>>Austin Holland: It takes a few days to build one of these things, and of course they're
not cheap. They're very sensitive seismic equipment. They record earthquakes of magnitude
4 plus around the world. Or if you put them to close to trains or roads, you get to record
a lot of cars and trains as well.
>>Dr. Puls: So a lot of this activity lately has been happening in the Edmond area, some
of it's been happening down south, south central Oklahoma. Is there some kind of relationship
in terms of where these occurrences are, in terms of other activities, in terms of faults,
and that kind of thing?
>>Austin Holland: So a large part of our seismicity, both current and in the past, occurs within
about 35 miles of the Nemaha fault system. It's a very large fault system, it runs from
south central Oklahoma up, sort of parallel to I-35 on into Kansas and then on up into
Nebraska. So it's a very large complex fault system with a lot of blocks and associated
secondary structures and that sort of thing. And most of our seismicity occurs within some
35 miles of that fault. But a lot of it is you know, kind of spread out and broad. We've
been seeing activity continuing in eastern Oklahoma counties at a very significant rate
for four years now. So that's a very long time to have this up, very increased level
of seismic activity in this optic for four years. And it's a truly a remarkable earthquake
swarm. It's been a little bit bewildering since we started looking at it. Some of these
Edmond 'quakes look like the northwest extension of that, and then some look a little different.
So you know, there's always a difficulty in understanding what's going on deep inside
the earth when we can't see it but through these very crude methods in a way.
>>Dr. Puls: So there's been some connections made in, in other states with recent earthquake
activity, such as Arkansas, Texas, Ohio, where they're making a connection between increased
earthquake activity and the disposal of wastewater from oil and gas operations and deep underground
injection wells. Does that have something to do with the increased uptick in activity?
>>Austin Holland: it's likely that it does. So identifying the cases that might be related
to theses saltwater disposal wells is really quite a challenge here in Oklahoma, because
these things have been operating for decades and years. It is a real challenge to find
the links. We have more than 10,000 UIC class two wells. That's the, the wells that are
allowed to inject for oil and gas activities into these deep aquifers that don't contain
drinking water. And so, you know, that's something we're looking at. Identifying which sequences
might be related to, a saltwater disposal is a real challenge. We had a recent case
in Love County just north of Marietta where there's a series of earthquakes that occurred
about two weeks after injection started in a well. But this area's had earthquakes swarms
that have been shallow in the past. OGS has tried to put out instruments to record these
swarms, and has been unable to get good locations for these earthquakes. And so we were able
to get some instruments out and record some really good data for these earthquakes. And
we're working on a project that would allow us to state with scientific accuracy whether
earthquakes are caused by re-injecting in that well or, or not. So we're looking at
ways to accurately identify cases where we can say that wells may be causing earthquakes.
But it is continuing work and we're working on these sorts of cases all the time. It seems
like every new sequence the earthquakes someone suggests disposal wells. And of course we're
continuing to look into that.
>>Dr. Puls: So what would be the mechanism in terms of you know if, if, if the seismic
activity is in fact induced because of wastewater disposal what would be the mechanism that
would cause that?
>>Austin Holland: What you have to have is an Earth that's basically critically stressed.
You have a fault that's at that rupture point where it just takes a small amount of change
to cause it to rupture. And so the, the actual mechanism that's generally turned to, to trigger
these earthquakes is you are injecting pressure in the subsurface or water at pressure in
the subsurface. And sometimes this can be pretty low pressure, but as the water builds
a column in the well it can generate significant pressures. And so this pressure then is transmitted
through the Earth, and so it moves slowly but faster than the actual water travels and
this pressure than can interact with these faults. You effectively reduce the friction
on the fault. So you partly push the fault apart ever so slightly with this additional
pressure, and if the faults ready to slip then it can slip.
>>Dr. Puls: We've talked in this course earlier about the role of the Oklahoma Cooperation
Commission in the state in terms of being the regulatory entity for oil and gas. They're
also the regulatory entity for the UIC program, the Underground Injection Control program.
Have you been working with them at all on this issue?
>>Austin Holland: Absolutely. We're in contact probably every week, if not every day at times.
So you know we work closely together. Of course the Geological Survey is not a regulatory
body, we're a research and public information body; and so we try to inform them with the
best science we can. And hopefully help them make good decisions and, and just provide
them the information that we can provide that they don't have the expertise to provide themselves.
>>Dr. Puls: What about the Oklahoma Geological Survey in terms of the public. Do you do things
to perhaps help the public better understand what's going on?
>>Austin Holland: Absolutely. So at times we've held town hall meetings. I do a lot
of talks to civic groups. I give interviews to the media. We do whatever we can to inform
the public. We release a lot of publications that are available to the public, and we don't
copyright our material so others can use that material for educational purposes. So a big
part of our mission is interacting and educating the public.
>>Dr. Puls: Well, I'm glad you had time to stop in today and, and talk with us. We really
appreciate it.
>>Dr. Puls and Austin Holland: Thank you.