Thursday, April 10, 2014

Not every oil spill is the same...

Oil-covered rocks at Coal Oil Point near the University of California, Santa Barbara.
If you did not know it, you would think these splotches of oil painted on these rocks were from an oil spill.
They were but not from humans -- they are from natural seeps. (Photo credit: Chris Reddy, WHOI)
The grey-colored rocks with the holes are actually
chunks of oiled that have weathered or changed
so much through time that they have become solid.
If you hit them with a hammer, you can still smell oil.
(Photo credit:  Chris Reddy, WHOI)
Not every oil spill is the same and there is an adage that oil spills are like buying a house, “location, location, location.” And crude oils and their distilled products are like people —  “they each have their own personality”. This personality makes some oils more toxic, some more likely to evaporate, some easier to clean-up, and some harder to analyze. Hence, the fate, toxicity, and how to clean-up oil spills, for example, is also dictated by their personality. So if you couple that spills can differ based on where they occur and what type of oil, you get a wide range of potential outcomes a challenge. 

Yet, studying different spills does provide an opportunity to compare and contrast them, pushing us to understand how oil evolves once in the environment. Like many other aspects of science, we can incrementally learn about oil spills by studying each one. In this case, my laboratory members, colleagues, and I have been busy the past week collecting samples in Texas (Texas City spill: 2014), Louisiana (Deepwater Horizon: 2010), and California (oil seeps: on-going for a long time). 

Oiled sand-patties found in Grand Isle, LA
that are telltale remnants of the
Deepwater Horizon. Please note a new
APP we use called SOLOCATOR.
Using your smartphone with
SOLOCATOR, your pictures
get stamped with the time
and location.
(Photo credit: Chris Reddy, WHOI)
Please see recent blog posts by Bob Swarthout and Bob Nelson ("the two Bobs") from my laboratory about their work on the Texas City spill. I collected samples from Santa Barbara, CA last week while on vacation with my wife, Bryce. I guess this may not bode well for our marriage, but my wife didn’t mind. Both her and I were astonished to see so much oil on the beaches of Santa Barbara that have nothing to do with humans. Rather natural seepage of oil from cracks in petroleum reservoirs that percolate up into the ocean. I have been studying seeps for the past 10 years as they are living laboratories and because they are occurring every day.  So, it’s a great chance to capture the earliest moments of when oil interacts with water and air, and if you look carefully, where oil has been on nearby coastlines for thousands of years. 

Christoph Aeppli.
A few days ago, I traveled to Grand Isle, LA with my colleague, Christoph Aeppli, to collect remnants from the Deepwater Horizon (as part of a long-term project initiated in 2011). We can still find traces of oil at this site. What was so surprising about Grand Isle and nearby Elmer’s Island was the presence of different oiled-samples. We could see the characteristic oiled sand-patties with their orange tint from the Deepwater Horizon. To be prudent, we will have to fingerprint the oil residues back in my lab but the color and shape of these patties is pretty much telltale. 

What was surprising was that we observed many samples that appear to be oil in nature that looked like hockey pucks and had a soft, rubber-like consistency. We have seen similar samples at this location over the years and determined that they were not from the Deepwater Horizon. I expect the same but will need to confirm it. What this means is that not every sample found on the Gulf coast can presumably be from the Deepwater Horizon, which is entirely reasonable considering the region’s past and active drilling and natural seeps, too. 

“Skid marks” on the beach in Grand Isle, LA that have an orange tint similar to other samples from the
Deepwater Horizon. (Photo credit: Chris Reddy, WHOI)
Last, we noticed orange-brown patches of sand that looked like skid marks. Again, we will need to check the source of this oil but it looks like its from Deepwater Horizon. While I have been to Grand Isle many times and other Gulf beaches, I have never seen these patches. 

Unusual oil-like samples found on Grand Isle.
We will need to test the oil to find out its source.
(Photo credit: Chris Reddy, WHOI)
Fieldwork is the first step of many when studying oil spills. It can be fun to be out of the laboratory or not writing emails, but its hard work. You have to pay attention to the surroundings and take good notes. You have to be meticulous when archiving the samples. Occasionally back in the lab, a sample’s label does not match our notes. When this happens, we have to throw out the sample. If not, we will always have some doubt when considering it. Nature is not a controlled setting like a laboratory, providing us with so many variables. The last thing we want is one more, like the questionable provenance of a sample. 

With the samples back in the lab or on their way, we will determine the type of oil in these samples which ones our similar or not, and ascertain how nature may have changed or “weathered” the oil. Like a jigsaw puzzle, we hope that we can add a few pieces to the science of spills from these trips. And maybe, we might get a corner piece! 

Post Author:
Dr, Chris Reddy
Woods Hole Oceanographic Institution

1 comment:

  1. oil spills are closely monitored through EMSA's CleanSeaNet equipment.

    ReplyDelete