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Monolithic Logic

Two substantial rockfalls at the east end of El Capitan (near where Horsetail Falls sometimes appears) have resulted in one death and two injuries. Frankly with all the climbers and tourists it is kind of surprising that this is limit of the human toll. This corner of the face of El Capitan seems to have had less activity prior to this than some other nearby corners of Yosemite.  Things could be a lot worse: Stock and Uhrhammer (2010) dated the very large rock avalanche from the east face of El Capitan to about 3600 years ago (in red on map below excerpted from Wieczorek et al., 1999), and a couple other younger rockfalls have come off El Capitan in historic time (the orange areas on the map). From the photos out there, GG has guessed at the approximate location of the debris that came down this past week (added to map below; the rockfall source is on an essentially vertical rock face).

YoseRockfallMapYoseRockfallKey

Anyways, the intent here is not to consider the geology of this so much as a controversy that coverage of this event has sparked in some corners, namely, is El Capitan the “largest granite monolith” as termed by some reports?

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Whose Fault?

Kerry Emanuel, a climate scientist at MIT who is perhaps best known for arguing that in a warming climate, hurricanes will be stronger, wrote an op-ed for the Washington Post basically saying that it is high time to recognize that disasters are not entirely natural.  Well, he was bit stronger than that:

We must first recognize the phrase “natural disaster” for what it is: a sham we hide behind to avoid our own culpability. Hurricanes, floods, earthquakes and wildfires are part of nature, and the natural world has long ago adapted to them. Disasters occur when we move to risky places and build inadequate infrastructure.

So there are no natural disasters? Op-eds like this are to challenge the reader and try to get that reader to come to grips with uncomfortable facts.  Reading the comments online suggests it didn’t really do that…. But here we can parse things more finely. There is both truth and exaggeration in Emanuel’s piece.

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Oklahoma Quakes, the Infrastructure Side

Last November, a M5.0 quake caused some damage in Cushing, Oklahoma.  A number of folks at the time were relieved that there wasn’t any noticeable damage to the nation’s largest oil storage facility.  This was only a few months after the Oklahoma Corporation Commission ordered a cutback in disposal of wastewater in injection wells. Since then, seismicity has mostly quieted down, but it seems that recognition of the scale of the hazard has been seeping into the awareness of a broader part of the media, leading to a lengthy piece in Politico Magazine on the potential disaster lurking in Cushing from facilities not really designed to survive an earthquake. While most of the stories of earthquake hazards in Oklahoma have been more focused on falling chimneys and old brick buildings, this piece exposes a pretty critical flaw in Oklahoma’s infrastructure.

So we will hope that there isn’t another unrecognized fault slowly being lubed up under Cushing.  But remember, the largest events from the infamous Rocky Mountain Arsenal injection adventure in the 1960s came more than a year after injection was totally stopped.  Oklahoma hasn’t stopped injecting fluids, and the volume of water injected so far dwarfs anything that happened in Denver in the 1960s…

Exodus

Geologists have for a long, long time been telling people not to build things in certain places.  Barrier islands? They move and evolve, which means property comes and goes. Not good.  Floodplains? They, um, get flooded.  Landslides? Only if you want a mobile home with a mobile yard. Sometimes we get heard, but usually we don’t. And the more subtle stuff, like recognizing how paving large areas can make floods worse? Lots of luck there. Doesn’t matter if the communities are rich or poor, building in bad places seems a national habit.

Maybe that is changing.

Even as the national media seems to just be noting that flood insurance is encouraging building in vulnerable spots, Politico has a big story on Louisiana’s program to consider how some communities will be forced to move and how to prepare to absorb that exodus as it occurs. For the Grumpy Geophysicist, this is a moment of actual hope, a ray of sunshine in the currently clouded over world of using science to guide public policy. [If you want more darkness, consider that politicians are rewarded for disaster relief and not disaster preparedness.]

The basic point is that people don’t like getting hammered by really bad weather (you know, like floods).  And so they leave–and this isn’t typically a slow migration but instead a real wave of refugees from hurricanes or floods or other such unpleasantries. They don’t often go really far away, so neighboring communities suddenly are flooded with people. There are two main forks to preparing for this: one is to try and get the vulnerable communities to start to think about how they will evolve in the face of the next storm, and the other is for those neighboring communities to prepare for the eventual migration of their neighbors. The state is actively trying to do this kind of work.

While there are uncertainties in our future, there are a few things that will happen.  There will be sea level rise.  There will be bigger rainfall events. These are both so clearly tied to the basic physics of increasing CO2 in the atmosphere that there really is no avoiding them; the best we can do now on that side of the ledger is to try and keep the magnitudes lower than they might otherwise be (and some areas also see land subsidence, which is unrelated to global warming but also causes problems). So we need to prepare, which means surrendering land we cannot defend and defending land we dare not surrender.

That Louisiana is starting to consider this landscape triage may just mean we’ve moved off the “we will rebuild it” mantra of the past century. As the article makes clear, this won’t be easy–but it should be much better than letting the chaos of the next disaster drive change.

Courting Disaster

For those of us in earth science, this past week has highlighted an awful lot of potential “told you so” moments. Like how warming climate and a warming ocean will lead to higher precipitation events. Like how you really do need to plan for floods. And we just missed hearing more about the barrier island/marsh protection talking point. And almost at the same time we’ve been greeted with ever more evidence that the Trump administration has little or no use for scientific input–not even choosing to ignore it, they seem more eager to simply not have any scientific input at all. Just as it is ever clearer that we are facing real decisions in trying to prepare for a warmer world, we seem the have a government yelling “la la LA LA” with its fingers in its ears.

But that isn’t the point here today.

One aspect of the tragedy in Houston is that the absence of any sensible planning has led to more flooding (the worst example might well be letting houses be built within the basin and below the spillway elevation of flood control dams); this is exacerbated by the combination of government subsidized flood insurance and the out-of-date or inadequate flood zone maps. Of course some now point to the zoning-free and laissez-faire approach to building in Texas as the bargain they made with the devil, implying that other places where strict zoning has been enforced will be safer.

Dream on.

If GG has noticed one thing about strict zoning (and Boulder has a pretty heavy hand on building), it is that it is rarely used to prevent building in stupid places–it is mainly used to keep people from building on land other people enjoy as it is. Some years ago when Colorado Springs was approached by a developer who wanted to build houses on an active landslide, the city council had to look away from the evidence they were given in order to approve this ongoing disaster. You can find similar stories elsewhere. Yes, fear of flooding is brought up when a new development is proposed…but mainly as part of the larger arsenal serving Fort NIMBY (sometimes there is a legitimate fear, but sometimes it is greatly exaggerated). California has the Alquist-Priolo act to prevent construction near active faults, but it only moves buildings 50 feet from an active fault.  Direct destruction of a building by a fault being directly under it is one of the least likely modes of destruction (even some dams do OK on faults: the Upper Crystal Springs dam survived having several feet of offset in the 1906 earthquake). Earthquakes do most damage by shaking weak soils: recall the Marina District in San Francisco, far from surface faulting, where shaking from the Loma Prieta earthquake damaged dozens of structures. What strict zoning clearly does is raise housing prices.

The main exceptions to non-use of zoning as a disaster preventative is in the wake of disasters. Even then, the most common refrain after a disaster is “we’re going to rebuild and bring it back better than before.”  After a tornado, this makes sense.  After a flood, whether storm surge or heavy rain? Not so much. The harder statement? “We learned a lesson and we aren’t going to make that mistake again.” It is very hard to say, but if we are going to avoid paying to rebuild over and over again in increasingly vulnerable places, risking the lives of inhabitants in the meantime, it’s time to start saying it and then walking the walk.

 

All quiet on the plains…

Its been awhile since Oklahoma earthquakes made news and so it seems timely to look in on the Sooner State to see how things are going.

Last we looked in, numbers of earthquakes were down but the moment release was still pretty high. Predictions from Stanford late last year were that the decreased injection of wastewater would lead to a decrease in earthquakes over the succeeding five years. The USGS, in contrast, has continued to note that the decrease in the number of events does not mean a decrease in damaging earthquakes.

So far, the news is good.  Not too surprisingly, the number of earthquakes continues to drop:

OKEQ-2015_to_7-17

So that continues the trend from 2016.  What about moment release?  Well, given the absence of news reports, you’d guess there is a decline there, too, and you’d be right:

OK_Cum_moment_to_7-17

And, indeed, 2017 has been dead quiet moment-wise as well.

Does this mean that the seismic risk is now gone?  Well, no.  That M5.7 earthquake in late summer last year was on an unrecognized fault.  The fluids migrating in the basement could encounter another critically stressed fault and trigger a significant earthquake. But for now, this is good news for Oklahoma residents.

Rock, teach oil, or maybe vice versa

GG attended a workshop here at CU on lessons from mining that could help guide oil and gas development (since the conveners encouraged outcomes to be shared on social media, figure this is OK). In kind of an odd way, the focus was more on what happens at the end of mining or oil development more than what happens at the start, so that will tend to be the focus here.

So a quick summary of points GG noticed.

  • Mining is highly focused, oil and gas far more distributed with a web of infrastructure.
  • Mines active today have to meet bonding requirements and increasingly have to have reclamation plans; oil and gas wells have far less specific requirements (e.g., bonding is not by well but by state or even nation).
  • Mines are a single use of the land; oil and gas production often shares the land with other rural uses.
  • Problem mines are problems for thousands of years–there is no true long term remediation. They can foul a lot of water for a long time. Wells are more insidious, typically failing silently until you know groundwater is compromised or a house blows up.
  • Mines these days are rarely totally shut down; they frequently are mothballed and then brought back online.  Oil and gas wells are frequently plugged and closed.
  • Mining’s main impact seems to be contaminating surface waters.  Oil and gas activity mainly affects subsurface waters.
  • Modern mining remains dominantly rural [save for mining towns!], but oil and gas has moved into suburbia. However, old mines are around a lot of western towns and there is renewed activity (and opposition) from time to time.

So what would the public want for post-development lands? In both cases, one can presume a safe environment available for any subsequent use. In many cases, they might want something resembling the pre-mining landscape. How realistic is this?

For mines, it depends on the mine. Big, modern open pit mines with sulfides are likely nearly hopeless. Strip mines for coal probably can be reclaimed provided they are not in areas where erosion is likely. Many small legacy mines can be shuttered to have an acceptably low level of impact. You can probably tell when a mine can be safely shut down.

For oil and gas wells, there is a surprisingly high level of uncertainty. Modern plugging procedures will usually work for the near term, but if gas continues to migrate up the well bore, any weaknesses that develop in the well plug or around the outside of the well bore will allow the gas to vent to the surface. Degradation of the well materials will connect shallow and deep aquifers, which can be troublesome if the deep aquifers have sufficient pressure to invade a shallower drinking water aquifer.  Or if the deep aquifer has negative pressure, you can lose drinking water to the deeper aquifer. That oil and gas wells are not of the same material as the surrounding rock means that it is likely over long periods of time that some kinds of failures of the well’s plug will occur (chemistry and stress will focus on that interface).  How often is this likely? How often will a failure produce surface problems? We really aren’t certain.

One suggested solution for problem mines is to make use of the waste material. This might help for acid mine drainage, but is less helpful for some other environmental hazards from mines. It is unlikely that a plugged oil or gas well that leaks has any economic utility.

So at the end, what does full closure of mines or wells look like?  Mines are unlikely to have their footprint totally erased, and some will be problems for centuries, but many others will be available for other uses. Oil and gas wells are tougher.  Most rules require a plugged well’s pad to be returned to something looking like the original landscape. When bonding is insufficient (as has been the case in Wyoming, for instance), failed companies’ wells might not be reclaimed. But even where surface reclamation is done (and oil and gas companies like to show pictures of old well sites to show they don’t look particularly bad), the well below is still subject to failure and leaking. While some mine sites might well be safe to build on (and many mountain resort towns are in fact built on old mine sites), building on an old well is playing a bit of Russian roulette. Shallow aquifers could fail as well. Perhaps monitoring for natural gas and pollutants in the water would permit full reoccupation of well sites, but it seems just as likely that rules will prevent building on or too near old well sites.

What do local communities need to know? They should probably understand that oil and gas wells are forever–plugged wells in most cases will cause no problems, but given that we haven’t watched a bunch of wells plugged with modern techniques for a really long time, that there is a non-zero risk of future leakage, and so monitoring appropriate for the subsequent use of the land should be required. Ripping out as much of the oil and gas infrastructure as possible is wise. For mines, it kind of depends. Any mine with underground workings can later collapse, so building on top of such mines should be considered with caution. If a mine is leaking colorful water into streams, odds are this will continue for centuries and some kind of action is desirable, but know there are not, at present, permanent fixes.