4.9 million barrels of oil, where did it go?
“It’s becoming a very elusive bunch of oil for us to find” – National Incident Commander Thad Allen
The federal government released a report last Wednesday claiming that about 75% of the more than 4.9 million barrels of oil spewed from BP’s blown out Macondo well has “evaporated or otherwise been contained.”
After reading which I thought: “...?..”
Really? Where did the oil go? The oil really evaporated?
The chart suggests that about one quarter of the oil that spilled from the well remains in the water, on shore, or in sand and sediments. One quarter of the oil is said to have evaporated or dissolved in the water, and the rest has been dispersed or collected (more on dispersion later).
OK…but, again, really evaporated? And why hasn’t all of the oil met the same fate? Why did some of the oil evaporate while some dissolved, and still other bits formed tar balls and washed ashore?
The answer, it seems, is that, according to Oil in the Sea III, a report published by the National Academy of Sciences, oil is a mixture of hundreds of compounds--including benzene, toluene, and heavy metals--the composition of which varies from source to source and over time. The hours-long journey that the oil makes from the well head to the ocean surface causes the oil to fractionate into its component chemicals, leading the heavier compounds to drift to the ocean bottom while the lighter compounds rise to the ocean surface.
Once at the surface, the lighter hydrocarbons, also known as light ends, are more prone to evaporation than are the heavier components. Rough seas, high wind, and high temperatures increase the rate of evaporation and the proportion of oil lost this way. The warm, turmultuous water of the gulf has therefore promoted evaporation of the lighter fractions of the spilled oil.
Some of the “hundreds of compounds” in oil are water soluble and dissolve into the surrounding water, a process that occurs more quickly when the oil is finely dispersed. The more soluble compounds turn out to also be the light aromatic hydrocarbons. Thus, the processes of evaporation and dissolution are lumped into one pie of the chart.
What about the 16% of the oil that has “naturally dispersed”? Like with dissolution and evaporation, the character of the oil and the state of the sea influence how much oil is naturally dispersed. Waves and turbulence at the sea surface can promote natural dispersion, causing an oil slick to break up into droplets which then become mixed into the upper levels of the water column. Dissolution, biodegradation, and sedimentation are more likely when the oil remains suspended in the water as droplets. Again, light, low viscosity oil is most prone to natural dispersion.
So the oil that has dissolved or dispersed (naturally or chemically) is not really gone. It is still in the water, it just can't be seen.
Also, unfortunately, some researchers remain wary that oil that has disappeared from the water's surface will reappear onshore in the future, as happened with the 1979 Ixtoc I oil spill. Larry McKinney, director of the Harte Institute for Gulf of Mexico Studies at Texas A&M, Corpus Christi, told Discovery News that dispersants similar to those used on the BP spill were used to break up the Ixtoc oil, which later washed ashore onto Texas beaches. McKinney is worried that the same thing will happen with this spill. "BP used a lot of dispersant and the oil went someplace," he said.
I am quite curious about the use of chemical dispersants with this spill and the microbes that are doing the degradation, so I am writing a post about it. If you are curious too, check out Petroleum to clean up petroleum? on the Buzz blog.
One last thing:
According to the New York Times, reaction to the report (and its associated chart) has been varied among scientists specializing in the issues it raises. In fact, Samantha Joye, a marine scientist at the University of Georgia told the Times that a lot of the report’s content is “based on modeling and extrapolation and very generous assumptions.” She said that the report would have been “torpedoed into a billion pieces” if it had been put out by an academic scientist.
On the other hand, Edward B. Overton of Louisiana State University said that the report might have underestimated the amount of oil that has effectively left the Gulf. See the Times for a full examination of the debate and the applicability of modeling for predicting the amount of oil that remains.
Apparently, massive earthquakes (reaching magnitudes of 7.0 and 8.0) struck Middle America between December 1911 and February 1812. (The largest of those quakes caused the Mississippi River to flow backwards temporarily!)
The area of the quakes, New Madrid Missouri, isn’t located at the intersection of tectonic plates, so why did earthquakes of such magnitude strike there?
Courtesy National Center for Earth-surface Dynamics (NCED)Well, a paper recently published in the journal Nature suggests that the earthquakes were due to the actions of our beloved mighty Mississippi River.
The idea is that the Mississippi rapidly eroded tons of soil—39 feet of sediment from the river basin—at the end of the last ice age (around 16,000 years ago). That “quite dramatic” erosion (which occurred over a period of 6,000 years, but I guess is considered “rapid” in geological time) set in motion the events that would lead to the New Madrid quakes, as Roy Van Arsdale, a geologist and co-author of the study told msnbc.
Courtesy National Center for Earth-surface Dynamics (NCED)Van Arsdale and fellow authors suggest that the erosion of the sediment released a lot of weight from the Earth’s surface, causing it to buckle just like a stick that is bent from both ends. Imagine bending a stick in your mind, and you will see that in the middle, bending part of the stick, the top part curves upward and is stretched. The bottom part is compressed. In the case of the Earh's crust, the stretching creates faults, or cracks, in the crust. The study's authors suggest that the faults failed in 1811 and unleashed the Earthquakes of New Madrid.
So there you have it, earthquakes in the middle of the country (which is apparently the the country's most earthquake-prone region outside California! Who knew?!) caused by our old familiar mighty Mississippi.
A new record hail stone fell on 23 July 2010 near Vivian SD!
It is 8-inch in diameter hail stone and weighs 1.9375 pounds.
The old record heaviest U.S. hailstone was a 1.67-pound found near Coffeyville, KS on Sep. 3, 1970. The old record for the largest diameter hailstone was 7 inches found in Aurora, NE on June 22, 2003. This Aurora, NE hailstone still holds the U.S. record for circumference: 18.75 inches. The Vivian, SD hailstone circumference was only 18.5".
Hail is precipitation in the form of large balls or lumps of ice. Hailstones begin as small ice particles that grow primarily by accretion. The production of large hail requires a strong updraft that is tilted and an abundant supply of supercooled water. Because strong updrafts are required to generate large hailstones, it is not surprising to observe that hail is not randomly distributed in a thunderstorm; instead it occurs in regions near the strong updraft. Supercell thunderstorms, in which the strongest updrafts are created with help from the mesocyclone, often produce the largest hail.
Eventually, though, the weight of the hailstone overcomes the strength of the updraft, and it falls to earth. The curtain of hailstones that falls below the cloud base is called the hailshaft. These regions are often said to appear green to observers on the ground, although recent research suggests that heavy rain as well as hail can create this optical phenomenon. As the storm moves, it generates a hailswath, a section of ground covered with hail.
Hailstorms can severely damage crops, automobiles, and roofs. Sometimes the swath can be so big you can see it on the ground from a satellite
Whether you've been following the Deepwater Horizon (BP) oil spill or not, if you like theater, have I got a show for you!
A friend turned me on to Macondo playing at the Guthrie theater through this weekend (last show is Sunday, Aug. 1st at 1:00pm). The play is A Guthrie Experience for Actors in Training production, so tickets are only $10/each. I've posted the Guthrie's description of the play below, but if you want more information or to reserve your tickets, click here.
"Macondo is a place of myth, a place where oil spills under and over water, creating a chain reaction that devastates human lives and animal habitats. It is also the name of the ruptured BP undersea oil field and oil well responsible for the current Gulf of Mexico spill. The gods awake from their slumber and intervene in this dramatically unfolding story that currently weaves itself through the fabric of our lives."
The National Research Council’s conceptual framework which will guide the development of next generation standards for science education has just been released (today) for public comment.
Tropical Storm Alex, which formed over the northwestern Caribbean Sea out of a westward-moving tropical wave on Friday and Saturday (June 26 and27), emerged overnight into the Bay of Campeche from the Yucatan Peninsula. Since emerging from that landmass as a tropical depression (signifying sustained winds weaker than 35 knots), it has strengthened back to Tropical Storm status. Current forecasts place it as a hurricane — possibly major — near the northern Mexico Gulf Coast later this week.
Courtesy National Center for Earth-surface DynamicsThe Mississippi River has turned out to be a big, muddy, silent hero in the fight to save Louisiana's wetlands from the oil spill.
It turns out that many scientists believe that the flow of fresh water from the Mississippi River into the Gulf of Mexico has thus far kept the oil slick offshore and out of wetlands.
Guerry Holm, a researcher with the National Center for Earth-surface Dynamics (NCED) tells me that the flow of the Mississippi River has been at a relatively high stage for the past two months and that the river's high volume of freshwater has acted as a hydrologic barrier, keeping oil from moving into the Mississippi Delta wetlands from the sea. Holms is now studying how two river characteristics—the slope of the water surface from the river delta to the sea and the time it takes water to move through a wetland to the sea—help mitigate oil contamination of the wetlands.
Holm is collaborating on the research with NCED Principal Investigator Robert Twilley, who is also busy addressing an immediate concern: the flow of the Mississippi tends to drop seasonally, starting in June. If that happens and Mississippi water flow into the delta decreases, Twilley, Holm, and others worry that oil will reach more of the wetlands sooner.
To address these concerns, some area scientists are proposing to shift the flow of water between the Mississippi and a river in Louisiana it feeds called the Atchafalaya. Twilley supports the idea: "We've been in conversation with U.S. Army Corps of Engineers and the state [of Louisiana] about how to manage the river as a protection system," Twilley reports.
Unfortunately, the river flow adjustments may be difficult to accomplish for political reasons. The diversion structure used to control flow between the Mississippi and Atchafalaya Rivers is controlled by Congress. Earlier proposals to send more water down the Mississippi have been met with resistance.
I see the American Museum of Natural History in NY is going to have an exhibit on the Scott and Amundsen 'race' to the South Pole. (See NYTimes Art section: http://www.nytimes.com/2010/05/29/arts/design/29race.html?ref=arts ). I look forward to seeing that exhibit.
Being a weather guy.... Dr. Susan Solomon, a senior scientist at the NOAA and an IPCC author, has a book (The Coldest March: Scott`s Fatal Antarctic Expedition) that indicates that an unusually cold Antarctic autumn contributed to the death of Captain Robert F. Scott and his four comrades on their 1500-kilometer (900-mile) trek back from the South Pole in March 1912. Temperatures were 10° to 20° colder than expected during the race to the South Pole. The cold weather cut in half the distance the explorers could travel in a day. A blizzard trapped them in a tent, where they froze to death 18 kilometers (11 miles) from a supply depot.
Another fact I find interesting, is that the Scott expedition revealed that Antarctica once basked in warmth. Among the 16 kilograms (35 pounds) of rocks the expedition collected were fossils of Glossopteris, a seed fern. This fossil is scientific evidence that the current ice-covered continent was once fertile.
I enjoy working with our team to develop on-line interactive education activities. We are in the final testing of whose goal is to teach about the balance of global water, land coverage, atmosphere and cloudiness required to create a "liveable planet". If you want to play with it and give us feedback - here is the link:
The goal is to make a habitable planet by adding enough water, atmosphere and clouds to reach a global average temperature of about 15°C (59°F). You can mix and match, add or remove.
* Drag (and drop) an item from the right side to the left to add that element
* Drag (and drop) from the left are back to the right to remove that element
* HINT You must put at least 3 clouds by the planet!!
There is a timer to see how fast you can make the planet livable.
It's not every day that I agree with the NYTimes' John Tierney. But today, I do. He offers up seven rules for a new breed of environmentalist: the "Turq."
"No, that’s not a misspelling. The word is derived from Turquoise, which is Stewart Brand’s term for a new breed of environmentalist combining traditional green with a shade of blue, as in blue-sky open-minded thinking. A Turq, he hopes, will be an environmentalist guided by science, not nostalgia or technophobia."
Check out the rules. Are you a Turq? Does any of Tierney's advice surprise you?
Courtesy Cornelia Kopp
Jon Foley, of the University of Minnesota's Institute on the Environment, has similar advice. "There are no silver bullets," he says. "But there is silver buckshot."
Human activities, rather than nature, are now the driving force of change on the planet. And experts say that there will be nine billion of us on the planet by 2050. Making sure that we all have the chance to survive and thrive will require a lot of innovation, and a lot of blue-sky thinking. Who's up for the challenge?