Natural Seeps

Natural seepage of crude oil from geologic formations below the seafloor to the marine environment off North America is estimated to exceed 160,000 tonnes (47,000,000 gallons), and 600,000 tonnes (180,000,000 gallons) globally, each year. Natural processes are therefore, responsible for over 60 percent of the petroleum entering North American waters, and over 45 percent of the petroleum entering the marine environment worldwide.

Oil and gas extraction activities are often concentrated in regions where seeps form. Historically, slicks of oil from seeps have been attributed to releases from oil and gas platforms, and vice versa. In North America, the largest and best known natural seeps appear to be restricted to the Gulf of Mexico and the waters off of southern California, regions that also have extensive oil and gas production. As mentioned earlier, the seepage of crude oil to the environment tends to occur sporadically and at low rates.

Federal agencies, especially USGS, MMS, and NOAA, should work to develop more accurate techniques for estimating inputs from natural seeps, especially those adjacent to sensitive habitats. This effort will aid in distinguishing the effects of petroleum released by natural processes versus anthropogenic activities. Furthermore, areas surrounding natural seeps are extremely important natural laboratories for understanding crude oil behavior in the marine environment, as well as how marine life responds to the introduction of petroleum. Federal agencies, especially USGS, MMS, NSF, and NOAA, should work with industry and the academic community to develop and implement a program to understand the fate of petroleum released from natural seeps and the ecological response to these natural releases.

In search of the impact of the bp oil gusher. This article promises to contain the answer. I’ll try to clip from this book daily in search of an answer. If you would like to help post this information, answer questions that may arise, or do additional research, please let me know by email or comment here.

This is an ongoing post.  For all the posts so far click here.

PETROLEUM INPUTS TO THE SEA

An examination of reports from a variety of sources, including industry, government, and academic sources, indicate that although the sources of petroleum input to the sea are diverse, they can be categorized effectively into four major groups, natural seeps, petroleum extraction, petroleum transportation, and petroleum consumption.

Natural seeps are purely natural phenomena that occur when crude oil seeps from the geologic strata beneath the seafloor to the overlying water column. Recognized by geologists for decades as indicating the existence of potentially economic reserves of petroleum, these seeps release vast amounts of crude oil annually. Yet these large volumes are released at a rate low enough that the surrounding ecosystem can adapt and even thrive in their presence.

Petroleum extraction can result in releases of both crude oil and refined products as a result of human activities associated with efforts to explore for and produce petroleum. The nature and size of these releases is highly variable, but is restricted to areas where active oil and gas exploration and development are under way.

Petroleum transportation can result in releases of dramatically varying sizes, from major spills associated with tanker accidents such as the Exxon Valdez, to relatively small operational releases that occur regularly.

Petroleum consumption can result in releases as variable as the activities that consume petroleum. Yet, these typically small but frequent and widespread releases contribute the overwhelming majority of the petroleum that enters the sea due to human activity.

Based on analysis of data from a wide variety of sources, it appears that collectively these four categories of sources add, each year on average, about 260,000 metric tonnes (about 76,000,000 gallons) of petroleum to the waters off North America.

Annual worldwide estimates of petroleum input to the sea exceed 1,300,000 metric tonnes (about 380,000,000 gallons).

Although these are imposing figures, they are difficult to interpret in terms of their ecological significance, as they represent thousands or tens of thousands of individual releases whose combined effect on the environment is difficult to clearly establish.

Regional or worldwide estimates of petroleum entering the environment are useful only as a first order approximation of need for concern. Sources of frequent, large releases are rightfully recognized as areas where greater effort to reduce petroleum pollution should be concentrated, despite the fact that not every spill of equal size leads to the same environmental impact.

This study, as did the 1975 and 1985 NRC reports, attempts to develop a sense of what the major sources of petroleum entering the marine environment are, and whether these sources or the volume they introduce, have changed through time. Thus, this report not only attempts to quantify the amount released each year, but makes an effort to examine the geographic distribution and nature of releases of petroleum to the marine environment, as well as the processes that can mitigate or exacerbate the effect of these releases on the environment. Where appropriate, comparisons of estimates of petroleum pollution among studies over the last 25 years provide the basis needed to explore the performance for prevention efforts implemented during that time.

#1) Barack Obama has authorized the deployment of more than 17,000 National Guard members along the Gulf coast to be used “as needed” by state governors.  So what are all of these National Guard troops going to be doing exactly?  Are the troops going to be used to stop the oil or to control the public?

#2) Barack Obama has also announced the creation of a “Gulf recovery czar” who will be in charge of overseeing the restoration of the Gulf of Mexico region following the oil spill.  So is appointing a “czar” Obama’s idea of taking charge of a situation?

#4) It is being reported that 2.61 parts per million of Corexit 9500 (mixed with oil at a ratio of 1:1o) is lethal to 50% of fish exposed to it within 96 hours.  That means that 1 gallon of Corexit 9500/oil mixture is capable of rendering 383,141 gallons of water highly toxic to fish.  So why was BP allowed to dump 1,021,000 gallons of Corexit 9500 and Corexit 9527 into the Gulf of Mexico, and why aren’t they being stopped from dumping another 805,000 gallons of these dispersants that they have on order into the Gulf?

#5) If these dispersants are so incredibly toxic to fish, what are they going to do to crops?  What are they going to do to people?

#6) If the smell of the oil on some Gulf beaches is already so strong that it burns your nostrils, then what in the world is this oil doing to to wildlife that encounter it?

#7) Is it a bad sign that birds from the Gulf region are flocking north by the thousands?

#8) Why is BP being allowed to use private security contractors to keep the American people away from the oil cleanup sites?

#9) Why is BP openly attempting to manipulate the search results on sites like Google and Yahoo?

#10) Why has the FAA shut down the airspace above the Gulf of Mexico oil spill?  What don’t they want the American people to see?

#11) Senator Bill Nelson of Florida says that there are reports that there are additional ruptures in the sea floor from which oil is leaking.  If there are quite a few of these additional ruptures, then how in the world does BP expect to completely stop this oil leak?

#12) Why are scientists finding concentrations of methane at up to 10,000 times normal background levels in Gulf waters?

#13) At some testing stations in the Gulf of Mexico, levels of benzene have been detected at over 3000 parts per billion, and levels of hydrogen sulfide have been detected as high as 1192 parts per billion.  Considering that these levels would be highly toxic to humans, why hasn’t the general public been warned?

#14) Why are so many Gulf oil spill disaster workers showing up at local hospitals complaining of a “mysterious illness”?

#15) If “70% or 80%” of the protective booms are doing absolutely nothing at all to stop the oil, then what is going to stop the millions of gallons of oil in the Gulf from eventually reaching shore?

#16) It is being reported that the deepsea oil plumes are creating huge “dead zones” where all creatures are dying as they are deprived of oxygen.  If this oil spill continues to grow could the vast majority of the Gulf of Mexico become one gigantic “dead zone”?