Wednesday, November 16, 2016

"Chariots of Fire" to "Fire on Earth": Stream-of-consciousness from the Olympics to fossil charcoal/fire studies through poet William Blake


Until the gymnastics and swimming got underway, I hadn’t been watching much of this year’s summer Olympics. However, on the day after the opening ceremonies, I started my quadrennial games viewing odyssey with Chariots of Fire, the 1981 movie highlighting the athletic and faith journeys of two British runners, Harold Abrahams and Eric Liddell, to the 1924 Olympics. The movie story line begins and ends with the 1978 memorial service for Abrahams. The sequence at the end (https://www.youtube.com/watch?v=3vxlX5wyEQs) includes the hymn, “And did those feet in ancient time”, the unofficial hymn of England. (Some feel it should be the national anthem although there are dissenters: http://blogs.spectator.co.uk/2016/01/theres-nothing-patriotic-about-william-blakes-jerusalem/) The hymn has been included in other movies, such as Calendar Girls (sung in Women’s Institute meetings) and Four Weddings and a Funeral (sung during first wedding).

The lyrics for the hymn are from a poem by William Blake, written ~1804 (music* by Sir Hubert Parry). The movie title, Chariots of Fire, is from a phrase in the poem (at the end of the third poem stanza; in middle of second hymn verse), alluding to the Old Testament Bible description of the prophet Elijah being taken to heaven in a fiery chariot pulled by flaming horses. Other events and locations in the four-stanza poem, however, are not the standard Bible references of Reformation-to-early 20th-century Protestant hymns.  The first line queries if Jesus walked in England, possibly during his pre-ministry years, while the last lines of the second stanza ask “And was Jerusalem builded here, Among these dark Satanic mills”.

There are different interpretations of what Blake meant by “dark Satanic mills". Was he referring to the Albion Flour Mills, “first major factory in London” built in the early days of the Industrial Revolution, destroyed by fire in 1791, but not torn down for almost 20 years? The factory mill, when operational, threatened to ruin the livelihood of small local millers. Or was he referring metaphorically to establishment churches or major universities? Whatever Blake’s intention, images of soot-belching factories of the Industrial Revolution initially pop into one’s head.

One instance using the Industrial Revolution metaphor is found in Fire on Earth: An Introduction by Andrew Scott, David Bowman, William Bond, Stephen Pyne, and Martine Alexander (Wiley Blackwell, 2014; http://www.wiley.com/WileyCDA/WileyTitle/productCd-111995357X.html). The author of Chapter 12 writes, discussing the ‘Pyric Transition’ when civilization transitioned from biomass to fossil fuel usage:
     “For fire history, ‘industrialization’ is shorthand for that shift in fuel from surface biomass to fossil biomass, with all that means for how humanity applies and withholds fire on the land. Usefully, the general culture agrees, since popular imagination has long identified the Industrial Revolution with William Blake’s ‘dark satanic’ mills’ belching soot from combusted coals” (p. 231).


The book covers the history of “fire on earth” and the scientific methods of studying it. The authors include a geologist (Scott whose work, plus those of his colleagues and students, I have written about previously, http://carbonacea.blogspot.com/2014/10/paleo-wildfires-and-extinctions-at-gsa.html, http://carbonacea.blogspot.com/2014/10/wildfire-and-extinction-ii-gsa-2014.html), a botanist, ecologist, historian, and forester. All the authors’ research has involved aspects of fire science, how fire has affected landscape, ecosystems, and civilization, and the geologic and anthropological records preserving that information. I have not read the book from front to back, but have read or skimmed through sections that have particular interest to me.

Sixteen chapters are divided into four major parts: I) Fire in the Earth System; II) Biology of Fire; III) Anthropogenic Fire; IV) The Science and Art of Wildland Fire Behavior Management. The book’s Preface explains that each author spoke “in his own disciplinary tongue”, so the style of descriptive language may vary among chapters written by scientists versus historians. Following an introduction to what is fire and methods of studying fire (ancient and modern events), the historical flow of the book is from deep geologic time when plants (the fuel) first appeared on land (late Silurian/early Devonian, ~400 million years ago) to the present day. Some of the sections on fire in the geological record seem too short for my interest in that aspect, but the authors point out that the 390-page text is meant as an introduction to a topic that spans several disciplines. The references for each part, however, are comprehensive, and a companion website includes the figures and tables from the book, teaching material, and links to relevant websites, videos, podcasts.

This book is an excellent example of the value of interdisciplinary research in earth processes. As Scott writes in the online book description, fire is "an integral part of the study of geology, biology, human history, physics, and global chemistry".  In fact, this approach is very "Big History". Big History “examines long time frames using a multidisciplinary approach based on combining numerous disciplines from science and the humanities.”

I found particularly interesting, possibly from being an undergraduate history major before switching fields to earth science for grad school, the historical development of human interaction with fire, based on both historic documents and anthropological and geologic research into the last couple million years since the appearance of earliest human species. Man (using “man” and “his” as inclusive genderless terms) began his fire management relationship as a fire sustainer before he learned how to start or make a fire. The Chapter 11 author points out that man is the only creature that can control fire, and used it for cooking, warmth, land clearing, warfare. Eventually sustainable fresh wood/plant fuels for combustion could not keep up with demand, and, in the Pyric Transition during Industrialization, fossil plant-derived fuels (coal, petroleum, natural gas) became the primarily combustion sources (p. 231, 232).
Prometheus bringing fire to mankind (D'Aulaires' Book of Greek Myths, 1962)
 Fire is a natural process; we utilize it as a resource and tool, but also attempt to manage it as a natural disaster. Man has different relationships with various earth materials and processes, including what we call disasters because of their human disruption. For example, volcanoes, earthquakes, cyclones/hurricanes/tornados: we cannot control those, but try to lessen damage and injury through building codes or just getting out of the way. At the other end of the spectrum, various rock and fuel resources we exploit for civilization's benefit, and currently or retroactively try to ameliorate pollution and damage from extractive processes. Between these endpoints, fire, like surface water, we use and try to beneficially manage, but we cannot totally control.

The management of wildfires includes modern study of both physics and chemistry of burning plus methods to extinguish fires. The results of this research also benefit those trying to interpret the scale and intensity of fire events recorded in the rock record. Andrew Scott, his students and colleagues, particularly Claire Belcher and her own students, have made an important leap in interdisciplinary research in using modern fire science experimental techniques to interpret the fire record in the deep geologic past (hundreds of millions of years). Fusinite (the fossil charcoal 'maceral' in coal) and related combustion particulates in coals and sedimentary rocks are indicators of ancient wildfire. But, a better understanding of temperature and type of deep-time fire events and what the source material was (for example, plant or exposed/eroded coal deposit) has come from experiments testing the types of combustion products produced by various materials (https://sites.google.com/site/palaeofirelab/home; Fire Phenomena and the Earth System: An Interdisciplinary Guide to Fire Science).

This interdisciplinary approach to the analysis of geologic and prehistoric fire events, combining modern fire science, and geologic and anthropological charcoal/fire studies, is innovative. Fire on Earth, brings together related topics and useful avenues of research that could be easily missed otherwise if their results were published in specialty topic journals (not just physical versus social science journals but among narrowly specialized science/technology publications). Fire on Earth, similarly to how David Christian has described Big History in general, “help(s)” the reader “across the divide between the two cultures—from the sciences to the humanities” in the discussion of a millions-year-old natural process that has shaped civilization.

*I was recently surprised to find, regrettably at a funeral, that there is another hymn to the same tune but with different words: “O day of peace that dimly shines”. It was the closing anthem for the deceased, an English immigrant to the US, because the tune identifies so strongly with England.

**More on Big History:
https://www.bighistoryproject.com/home (Gates’ funded high school Big History project)


Tuesday, July 5, 2016

Particulate organic matter as paleocurrent indicators: dispersed fossil wood in Pennsylvania Bluestone

The tag line for this blog describes that posts are about geologic carbon, excluding carbonate and aqueous dissolved organic matter, focusing on sedimentary and metamorphic organic matter (OM=organic matter) and products from fossil fuel resources. I come at this topic from the organic petrology or microscopy methods I use to investigate geologic problems of level of diagenesis/ very-low-grade metamorphism or what assemblages of particulate organic matter can convey about depositional environment or climate. Many applications of or advancements in organic petrology are related to fossil fuel exploration or utilization, but there are other non-fossil-fuel applications of sedimentary OM data in the geologic sciences. However, in my experience and opinion, those are not commonly used, either because organic petrology is not part of the usual geology curriculum, therefore, not well known, or because light microscopy is not "high tech".

One occurrence of sedimentary OM greets me frequently while I am walking the dog. I live in an old neighborhood of lawns, large trees, and pachysandra (my personal trace plant for old neighborhoods); most of the homes were built around 1900. Although numerous sidewalks are now cement, many remain the original large slabs of Pennsylvania Bluestone, some with fossil wood fragments exposed on cut or slabbed surfaces. Pennsylvania Bluestone is a Middle to Upper Devonian feldspathic sandstone of the Catskill delta or Catskill/Pocono clastic wedge, outcropping now in southern New York, northeastern Pennsylvania, and northern New Jersey. It is the "molasse" of the Acadian orogeny, whose thermal and deformational peak in the northern Appalachians to the east (Maine, New Hampshire, Massachusetts, Connecticut) occurred in the Lower Devonian.

Bluestone in disrepair but shows typical sidewalk slab size and thickness. Twenty-pound (9 kg) puppy for scale.

Bluestone derives its name "from a deep-blue-colored sandstone first found in Ulster County, NY" (http://www.endlessmountainstone.com/bluestone/). In Pennsylvania, the focus of the bluestone industry is in Susquehanna County bordering New York state. Other colors include tans, various grays, and lilac/purple. The Endless Mountain Stone Company website (in 2002, Endless Mountain was the "largest  'bluestone' producer in Northeastern Pennsylvania, FCOFG field guide, p. 85*) also describes the quarrying, cutting or slabbing operations that produce stone for sidewalks, paving, building and facing stone. The environment of deposition of quarried stone includes offshore bars, beaches, and tidal interchannels.
Ripple marks (interference ripples?) on bluestone sidewalk slabs.

Ripple marks, in different location than above, on wet sidewalk in street lights at night.
Although the Pennsylvania Bluestone Association states that the stone is "clear of most organic residues", megascopic particulate fossil wood is occasionally visible. A stratigraphic section of one quarry in the 2002 Field Conference of Pennsylvania Geologists guidebook (Figure 79, p. 86) to the bluestone region, marks locations of "carbonized plant fossils" and "plant-bearing ss".
Patio bluestone showing range of color, some ripple marks, and, in slab in foreground, dispersed fossil wood fragments.
Old bluestone sidewalk slab; fossil wood weathered out leaving casts.

Fossil wood in both rippled and non-rippled bed surfaces in recently-quarried bluestone (in re-laid sidewalk using old original slabs and smaller new slabs to replace broken material). Fragments on non-rippled surface (lower left) show a general consistent orientation.
In the photo above, fossil wood, on the non-rippled bedding surface, is generally aligned due to the ancient water flow direction that deposited the layer and acts as a paleocurrent indicator. Such indicators include any elongated particles including graptolites and other fossils, and sedimentary structures such as ripples, crossbedding, and flute casts. However, alignment of linear objects, such as the wood fragments, can only narrow paleocurrent flow direction to two directions 180 degrees apart. Asymmetrical ripples and flute casts are examples of structures that can define a single direction. Below is an example of paleocurrent direction analysis, showing bidirectional results, from measuring orientation of wood fragments in a Devonian shale of the Appalachian/Catskill basin (in Potter and others, 1979, Devonian Paleocurrents in the Appalachian Basin).





Three more examples of oriented fossil wood in Pennsylvania Bluestone. Blue color in bottom two photos due primarily due to time of day, just prior to sunset.
(from Potter and others, 1979, Devonian Paleocurrents in the Appalachian Basin)

Above is the cumulative paleocurrent direction analysis of Appalachian Devonian sediments, including those of the Catskill/Pocono wedge, showing general western flow and deposition due to unroofing/erosion of the lower Devonian Acadian orogenic thermal/deformational axis to the east. Fossil wood fragments (=particulate land plant organic matter), such as that seen in the bluestone, were an important contributor to this data set.

BTW, at the time this post was written, the blog background was an extreme close-up of wood fragments in bluestone (below).


*Catskill delta field guides:
    Facies and Sedimentary Environments of the Catskill System Tract in Central Pennsylvania, Pittsburgh Association of Petroleum Geologists, 2009 http://www.papgrocks.org/PAPGGuidebook_Spring09.pdf
    From Tunkhannock to Starrucca: Bluestone, Glacial Lakes, and Great Bridges in the “Endless Mountains” of Northeastern Pennsylvania, Field Conference of Pennsylvania Geologists, 2009.

Sunday, May 1, 2016

Graptolite reflectance and correlation with other diagenetic and very-low-grade metamorphic indicators

My first independent organic petrology research project, in the late 1980's-early 1990's, was a graptolite reflectance study of the low- to very-low-grade metamorphic region of the northern US Appalachians in northern Maine. The goals were to 1) test the applicability of the technique, used in other anchizone regions, to these prehnite-pumpellyite grade rocks, and 2) outline in more detail the regional patterns or trends in metamorphism.

Graptolites are extinct colonial marine invertebrates of the Phylum Hemichordata with a geologic age range from Cambrian to Carboniferous. They derive their name from the pencil-mark appearance of preserved periderm on shales (Graptolithus= rock writing). Since the mid-1970's, the reflectance of graptolites, in a similar fashion to vitrinite reflectance, has been used to access the diagenetic level or organic maturity of rocks that, either due to a marine environment of deposition (EOD) or age older than the advent of land plants (pre-Silurian), lack vitrinite derived from woody plant matter. Graptolite reflectance has been applied to both petroleum source rock evaluation and analysis of patterns of anchizone metamorphism, the anchizone being the level of metamorphism between sedimentary rocks and greenschist facies where some diagenetic indicators may no longer be applicable and where big micas and flashy garnets, staurolite etc have not yet appeared. (In one talk in ~1992, I did compare the anchizone to the Neutral Zone of Star Trek, which separates Romulan space from Federation space; the anchizone is the area where neither those looking for liquid hydrocarbons nor those studying traditional metamorphic petrology care to go.)

However, the correlation of graptolite reflectance values to vitrinite reflectance has been problematic since vitrinite and graptolites are hardly ever found in the same rock, due again to age of rock or EOD. Correlation has been made through intermediaries: thermal maturity indicators found in or that can be applied to both vitrinite-bearing and graptolite-bearing rocks. Also, microscopically, some authors reported "maximum reflectance" in which, under polarized light (polarizer in light path), the microscopic stage is rotated to the orientation of the maximum reflectance of the highly anisotropic graptolite periderm and then reflectance is recorded. The mean of many maximum reflectance measurements on a rock sample can, therefore, be higher, with higher standard deviation, than "random reflectance", measured in non-polarized light. Correlation of graptolite reflectance with other indicators, such as conodont alteration indices (CAI), and with mineral-based metamorphic zone boundaries was also not clear, partly due to differing interpretations of the latter. But, fortunately, in 2007, the International Union of Geological Sciences (IUGS) published a classification for very-low to low grade metamorphic rocks (Árkai and others, 2007), which includes vitrinite reflectance, and standardizes boundaries for mineralogically-based diagenetic to low-grade metamorphic zones.

So a few years ago, partly for a couple papers still (even now) in draft form and partly in response to a petroleum industry colleague asking how well constrained the vitrinite/graptolite correlations are, I made a big spread sheet with the IUGS 2007 very-low-metamorphic indicators chart and correlation interpretations from numerous collected graptolite reflectance papers (references following). From that, I made the table BELOW showing THREE correlative relationships of graptolite reflectance: two from studies reporting random reflectance, but that use different intermediaries to relate graptolite to vitrinite reflectance and are from different geological provinces, and a third correlation of graptolite mean maximum reflectance.

TABLE (click on it to enlarge): Correlation of metamorphic facies, Kübler indices, vitrinite reflectance, and coal grade from the IUGS Subcommission on the Systematics of Metamorphic Rocks (Árkai et al., 2007); metapelitic zones to vitrinite reflectance and Kübler index (Abad, 2007); CAI (conodont alteration index) to vitrinite reflectance (Repetski et al., 2008); mean random graptolite reflectance, non-polarized light (to vitrinite reflectance through chitinozoan reflectance: Bertrand, 1990); mean random graptolite reflectance, non-polarized light (to vitrinite reflectance through RockEval pyrolysis Tmax: Petersen et al., 2013);  mean maximum graptolite reflectance to CAI or metamorphic facies (compilation of results from Oliver, 1988; Goodarzi, 1990; Goodarzi et al., 1992; Wang et al., 1993; Malinconico, 1992, unpublished data).

A very comprehensive correlation chart (their Figure 26) and discussion of numerous visual organic maturity Indicators by Hartkopf-Fröder and others was published in 2015. They included coal rank, reflectance of vitrinite, graptolites and other zooclasts, coloration of conodonts, spores/pollen and other microfossils, and hydrocarbon generation zones, but did not include mineral metamorphic facies. Three graptolite reflectance scales are in their chart: Petersen and others (2013) and two by Bertrand and colleagues. Their bibliography includes graptolite reflectance citations (such as several by Bertrand) that are not listed below.

These tables do not solve the graptolite/vitrinite reflectance correlation problem. They do, however, show state of the current publicly available knowledge.




GRAPTOLITE REFLECTANCE CITATIONS
and references for other diagenetic to very-low-metamorphic indicators
used in making the correlation table (in bold)

Abad, I., 2007, Physical meaning and applications of the illite Kübler index: measuring reaction progress in low-grade metamorphism, in Nieto, F., and Jiménez-Millán, J., eds., Diagenesis and Low-Temperature Metamorphism. Theory, Methods and Regional Aspects: Seminarios de la Sociedad Española de Mineralogia, v. 3, p. 53-64.
Árkai, P., Sassi, F., Desmons, J., 2007, Very low- to low-grade metamorphic rocks (Chapter 2.5), in Fettes, D., and Desmons, J., eds., Metamorphic Rocks: A Classification and Glossary of Terms (Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Metamorphic Rocks): Cambridge, UK, Cambridge University Press, p. 36-42.
Bertrand, R., 1990, Correlations among the reflectances of vitrinite, chitinozoans, graptolites, and scolecodonts: Organic Geochemistry, v. 15, no. 6, p. 565-574.
Bertrand, R., and Heroux, Y., 1987, Chitinozoan, graptolite and scolecodont reflectance as an alternative to vitrinite and pyrobitumen reflectance in Ordovician and Silurian strata, Anticosti Island, Quebec, Canada, American Association of Petroleum Geologists Bulletin, v. 71, p. 951-957.
Bustin, R., M., Link, D., and Goodarzi, F., 1989, Optical properties and chemistry of graptolite periderm following laboratory simulated maturation: Organic Geochemistry, v. 14, p. 355-364.
Cardott, B. J., and Kidwai, M. A., 1991, Graptolite reflectance as a potential thermal-maturation indicator, in K. S. Johnson, ed., Late Cambrian-Ordovician geology of the southern Midcontinent, 1989 symposium: Oklahoma Geological Survey Circular 92, p. 203-209.
Clausen, C.-D. and Teichmüller, M., 1982, Die Bedeutung der Graptolithenfragmente im Paläozoikum von Soest-Erwitte für Stratigraphie und Inkohlung: Fortschritte in der Geologie von Rheinland und Westfalen, v. 30, p. 145-167.
Cole, G. A., 1994, Graptolite-chitinozoan reflectance and its relationship to other geochemical maturity indicators in the Silurian Qusaiba shale, Saudi Arabia: Energy & Fuels., v. 8, p. 1443-1459.
Goodarzi, F., 1984, Organic petrology of graptolite fragments from Turkey: Marine and Petroleum Geology, v. 1, p. 202-210.
Goodarzi, F., 1984, Organic petrology of graptolite fragments from Turkey: Marine and Petroleum Geology, v. 1, p. 202-210
Goodarzi, F., 1985, Dispersion of optical properties of graptolite epiderms in increase maturity in early Paleozoic organic sediment: Fuel, v. 64, p. 1735-1740.
Goodarzi, F., 1990, Graptolite reflectance and thermal maturity of Lower Paleozoic rocks, in V. F. Nuccio and C. E. Barker, eds., Applications of thermal maturity studies to energy exploration: SEPM, Rocky Mountain Section, p. 19-22.
Goodarzi, F., Gentzis, T., Harrison, C., and Thorsteinsson, R., 1992, The significance of graptolite reflectance in regional thermal maturity studies, Queen Elizabeth islands, Arctic Canada: Organic Geochemistry, v. 18, no. 3., p. 347-357.
Goodarzi, F., and Norford, B. S., 1985, Graptolites as indicators of the temperature histories of rocks: International Journal of Coal Geology, v. 11, p. 127-141.
Hartkopf-Fröder, C., Königshof, P., Littke, R., Schwarzbauer, J., 2015, Optical thermal maturity parameters and organic geochemical alteration at low grade diagenesis to anchimetamorphism: A Review: International Journal of Coal Geology, v. 150-151, p. 74-119.
Hower, J. C., and Malinconico, M. L., 2000, Organic metamorphism in Middle Ordovician carbonates, Lebanon Valley nappe, Pennsylvania:  International Journal of Coal Geology, v. 42, p. 221-230.
Kurylowicz, L. E., Ozimic, S., McKirdy, D. M., Kantsler, A. J. and Cook, A. C., 1976, Reservoir and source rock potential of the Larapinta Group, Amadeus Basin, Central Australia: Australian Petroleum Exploration Association Journal, v. 16, p. 44-65.
Malinconico, M. L., 1992, Graptolite reflectance in the prehnite- pumpellyite zone, northern Maine, U.S.A.: Organic Geochemistry, v. 18, p. 263-271.
Malinconico, M. L., 1993, Reflectance cross-plot analysis of graptolites from the anchi-metamorphic region of northern Maine, USA: Organic Geochemistry, v. 20, p. 197-207.
Oliver, G. J. H., 1988, Arenig to Wenlock regional metamorphism in the paratectonic Caledonides of the British Isles- a review, in Harris, A. L. I., and Fettes, D. J., eds., The Caledonian-Appalachian Orogen: Geological Society (London) Special Publication 38, p. 347-363.
Petersen, H. I., Schovsbo, N. H., Nielsen, A. T., 2013, Reflectance measurements of zooclasts and solid bitumen in Lower Paleozoic shales, southern Scandinavia: Correlation to vitrinite reflectance: International Journal of Coal Geology, v. 114 , p. 1-18.
Rantitsch, G., 1995, Coalification and graphitization of graptolites in the anchizone and lower epizone: International Journal of Coal Geology, v. 27, p. 1-22.
Repetski, J. E., Ryder, R. T., Weary, D. J., Harris, A. G, and Trippi, M. H., 2008, Thermal maturity patterns (CAI and %Ro) in Upper Ordovician and Lower-Middle Devonian rocks of  the Appalachian basin: A major revision of USGS Map I-917-E using new subsurface collections: U.S. Geological Survey Scientific Investigations Map 3006, one CD-ROM.
Riediger, C., Goodarzi, F., and MacQueen, R. W., 1989, Graptolites as indicators of regional maturity in lower Paleozoic sediments, Selwyn Basin, Yukon and Northwest Territories, Canada: Canadian Journal of Earth Sciences, v. 26, p. 2003-2015.
Ruble, T. E., Knowles, W. R., Selleck, B. W., Wylie, A. S., 2013, Assessment of thermal maturation in outcrop samples of the Utica Shale, northern Appalachian basin, New York: American Association of Petroleum Geologists 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, AAPG Search and Discovery Article #90163 (www.searchandiscovery.com; accessed August 2013). 
Taylor, G. H., Teichmüller, M., Davis, A., Diessel, C. F. K., Littke, R., Robert, P., 1998, Organic petrology: Gebrüder Borntraeger, Berlin, 704 pages.
Teichmüller, M., 1978, Nachweis von Graptolithen-Periderm in geschieferten Gesteinen mit Hilfe kohlenpetrologischer Methoden: Neues Jahrbuch für Geologie und Paläontologie, Mh. 7, 430-447.
Wang, X. F., Hoffknecht, A., Xiao, J. X., Chen S. Q., Li Z. H., Brocke, R. B., and Erdtmann, B-D., 1993, Graptolite, chitinozoan, and scolecodont reflectances and their use as indicators of thermal maturity: Acta Geologica Sinica, v. 6, no. 1, p. 93-105.
Yang, C., and Hesse, R., 1993, Diagenesis and anchimetamorphism in an overthrust belt, external domain of the Taconian Orogen, southern Canadian Appalachians—II. Paleogeothermal gradients derived from maturation of different types of organic matter: Organic Geochemistry, v. 20, p. 381-403.

Monday, April 4, 2016

How BIG is BIG? (Data out of context and spinning the message: US Atlantic OCS and other oil reserve estimates in the news)


Two weeks ago, the US Department of Interior announced that the US Atlantic Outer Continental Shelf (OCS) was removed from the 2017-2022 offshore lease sale (http://www.cnn.com/2016/03/15/politics/obama-drilling-atlantic-coast/index.html;
http://washpost.bloomberg.com/Story?docId=1376-O42VSQ6JTSEX01-2P7U5E8RTS87GP3EKFMV10Q903). The January 2015 Draft Proposed Program for the OCS 2017-2022 lease sale originally included parts of the Mid-Atlantic and South Atlantic planning areas from Virginia south to Georgia; the portion of the Mid-Atlantic planning area offshore of Delaware and Maryland, and the North Atlantic planning area (offshore New Jersey north to Maine) were not in the Draft Proposal (see Figure 1). On March 15, 2016, however, the Proposed Program (http://www.boem.gov/2017-2022-Proposed-Program-Decision/) was published and now excludes the entire US Atlantic OCS. This decision was welcomed by environmental groups, various members of the US Congress from Atlantic coastal states (http://www.menendez.senate.gov/news-and-events/press/east-coast-senators-introduce-bill-to-prevent-atlantic-offshore-drilling-say-killthedrill), NASA and the US Navy (https://www.washingtonpost.com/news/energy-environment/wp/2016/03/14/the-governments-atlantic-drilling-plan-takes-friendly-fire-from-the-pentagon/), and some coastal communities. However, industry (http://www.oilandgasinvestor.com/feds-nix-atlantic-five-year-offshore-lease-plan-842361), plus governors of southern states who were hoping offshore fossil fuel production would bring income to the states, were disappointed, to say the least. (It is important to note, that although there is federal revenue sharing from offshore lease royalties to some Gulf Coast states, there is no revenue sharing plan in place for Atlantic states.)

The news articles above mention the 2011 assessed mean amount of potential fossil fuel resources for the entire Atlantic OCS, which includes the North, Mid- and South Atlantic planning areas: 3.3 billion barrels of oil (Bbo) and 31.3 trillion cubic feet (Tcfg) of natural gas (http://www.boem.gov/uploadedFiles/2011_National_Assessment_Factsheet.pdf). The revised 2014 assessment adjusts those mean numbers upwards to 4.72 Bbo and 37.51 Tcfg. These numbers are for the "Undiscovered Technically Recoverable"* resources on the Atlantic continental shelf within the US Exclusive Economic Zone (EEZ) that extends 200 miles from the US coastline. The lease blocks, however, would start no closer than 50 miles offshore (contrary to Senator Menendez' tweeted anti-drilling but Photoshopped picture of an oil rig within sight of beachgoers**). The assessments are based on wells drilled, mostly dry or uneconomic, and seismic data collected before the early 1990’s moratorium on Atlantic OCS oil and gas resource development, and on study of "analogs" which are known hydrocarbon plays in similar geologic settings in other parts of the world. The assessment, besides reporting the mean estimated amount, also provides other probabilities of occurrence: for the entire Atlantic OCS, there is a 5% chance (2014 revised assessment) of 9.23 Bbo and 67.7 Tcfg, but a large (95%) chance there is only 1.32 Bbo and 11.8 Tcfg.

But is this estimated resource amount BIG? Is loss of access to the Atlantic OCS a major blow to the Nation's energy independence and security, as some articles suggest? Although industry and industry media outlets would understand the relevance of the assessed numbers in relation to oil reserves around the world, the general public does not. A BILLION sounds immense, so readers may think we are missing out on a large national resource by blocking development. Without context, that is, without comparisons to other data, the numbers may be misleading. From the map below (Figure 2), however, one can see that Atlantic mean assessed amounts are minor compared to the Gulf of Mexico, and less than offshore California where there is proven production. According to an article in Eos, March 17, 2016,
The removal of that lease sale would lower the projection of future U.S. oil production by about 0.1% and would lower the U.S. natural gas production projection by 0.06%, according to the Interior Department’s Bureau of Ocean Energy Management (BOEM). ‘Thus, the energy security of the United States will remain strong without offshore leasing in the Atlantic during the 2017–2022 program,’ BOEM states in the new OCS proposal.”

 Figure 2: Figure 5-6 from http://www.boem.gov/2017-2022-DPP/ (p. 101 of pdf): Assessment of UTRR of the OCS, 2011 (Atlantic OCS Updated 2014)

Another example of numbers out of context is also related to oil reserves. In the early-2000’s, whether or not to open the Alaska National Wildlife Refuge (ANWR) 1002 Area to drilling was a contentious and controversial topic. Many against drilling said there was only several months of oil there, based on data in a US Geological Survey (USGS) report (https://www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2010/Arctic-Refuge-Turns-Fifty.aspx). WHAT? This argument was used as a reason not to drill. The USGS 1998 petroleum assessment of the 1002 Area (http://pubs.usgs.gov/fs/fs-0028-01/fs-0028-01.pdf) states that the mean Technically Recoverable oil in the 1002 Area (not including Native Lands or offshore waters) is 7.7 Bbo.  According to the Congressional Record-Senate (April 18, 2002, p. 5027), Senator John Corzine (D-NJ) said ". . . Based on estimates from the U.S. Geological Survey, it is likely to have little more than 6 months' worth of capacity relative to 1 year of U.S. demand. The oil wouldn't even begin to be available for at least 10 years. And it wouldn't reach peak production for 20 years."

Corzine's statement does include the phase "relative to 1 year of U. S. demand" which is key to understanding what is meant by "6 months' worth of capacity". In 2002, US crude oil consumption was 19.761 million barrels of oil PER DAY. If you divide that daily consumption (million barrels per day) into the mean recoverable 1998 estimate for the entire 1002 area (7.7Bbo, undeformed plus smaller geologically deformed region), you get the equivalent of 388 days or, using 1 month=30 days, 12.9 months, of US oil usage. Using instead the 95%-probability estimate of 3.4 Bbo (in just the undeformed part of 1002), the result is 170 days or 5.7 months of US oil consumption. But, could the 1002 Area, if ever in production, produce 20 million barrels a day? Could it be the Nation’s sole source of petroleum? NO. The estimated 1002 Area peak production daily rate ranges from 600,000 - 1.9 million barrels/day from multiple wells over a total 50-60 year life of the field (http://dog.dnr.alaska.gov/Publications/Documents/OtherReports/Oil_Gas_in_ANWR_Review_2003-02.pdf, p.6; http://www.eia.gov/pub/oil_gas/petroleum/analysis_publications/arctic_national_wildlife_refuge/pdf/anwr101.pdf). For comparison, current daily production from the world's largest conventional oil field, Saudi Arabia's megagiant Ghawar field, is ~5 million barrels/day. For the 1002 Area, saying there is only 6 months of oil, without detailing how that number was calculated, without saying that it is supposed to be some sort of useful analogy, is deceptive.

Although here in the USA, we are in the height of "spin" season with the coming Presidential election, sound bites or media reports with partial information or numbers out of context happen at any time in any field, not just the earth sciences. A piece of data or information, no matter how accurate can, without revelation of how it was derived or if isolated from larger trends or data sets, lead to an incorrect assumption on the part of the listener or reader. This can occur by design, to twist or “spin” a meaning, or inadvertently, but for greatest transparency, educated discussion and informed decision making, complete data and background derivations must be available.

* Technically Recoverable means we have the drilling and production technology to access and produce the resource. Sometimes assessment estimates are given as "Economically Recoverable" which means what can be produced with a profit at a particular market price of oil/gas: if the price is too low, as we have seen in the last year, production of some resources, such as unconventional shale gas and shale oil, may not be cost effective.




oil rig original photo: http://www.shutterstock.com/s/offshore+rig/search.html?page=3&thumb_size=mosaic&inline=214057231)

KEYWORDS AND TERMS: "Atlantic Outer Continental Shelf", OCS, "offshore lease sale"

Sunday, March 13, 2016

Rubber duckies serving science (Plastic 1)


Having a young grandchild now, I am pulling out my children’s toys, boxed away for over 15 years, for a new round of use. Among the Brio train sets, Legos, stuffed animals, dolls, Bobo Fett’s space ship, and Teenage Mutant Ninja Turtles are a variety of bath toys. The tub toys include these simple floating animals that I bought in the mid to late-1980’s.

Three remaining tub toys from my original set of four.
In September 1994, I was surprised to see these tub toys on the front page (photo below) of the American Geophysical Union newsletter Eos (abstract:


The featured Eos tub toys had enjoyed a more cosmopolitan cruise venue than a bath tub, with about 29,000 of them floating across the Pacific to the northwest coast of North America (Gulf of Alaska) after the shipping container transporting them from their Asian birthplace fell off the ship during a storm in January 1992 and broke open. The full Eos article described their service to science tracking ocean currents. The authors, Curtis Ebbesmeyer and W. James Ingraham, modeled possible routes from "deployment" to landfall and predicted subsequent trajectories of duckies, etc that did not wash up on beaches.

Parameters affecting the pathway include, of course, ocean currents, plus "windage": the air resistance or effect of the wind on a moving object. Air currents had a greater effect on the early movement of the tub toys since they are light and ride high in the water. On the other hand, the Nike sneakers in the Eos photo above, from a shipment lost in the Central Pacific in 1990, usually floated upside down with the sole barely above the surface of the water. The higher windage of the tub toys increased their speed across the Pacific after initial entry into the sea, compared to models for objects with lower windage.

The Eos authors discussed the several types of planned and serendipitous ocean current trackers: messages-in-a-bottle (MIB), flotsam, scientific drift bottles. About 2% of planned scientific drift releases are recovered, so the ~400 tub toys recovered from November 1992-August 1993, and an equal amount reported subsequently, are the same order of magnitude. However, the absolute number found was large since typical scientific drift bottle releases at that time were usually only 500-1000 objects. For flotsam to be useful, their point of entry into the ocean must be known so that they aren't confused with other shoreline trash. The Nike shoes had unique identification numbers. The tub toys had no numbers, but from the rather sudden appearance of all four plastic animal types on beaches along the SE coast of Alaska, coupled with reports of the spill, confirmed the shipping flotsam connection.

Computer models projected that, after 2 years, some tub toys still at sea would enter the Bering Sea. Computer modeling of trajectories in earlier years (back to 1946) showed that due to interannual variability in currents, drift objects initially traveling eastward from the central north Pacific reached a turning point close to the west coast of North America, and then could go north, like the 1992 toys, and either circle counterclock-wise around an eastern sub-orbit of the Subarctic Gyre or continue west to the Bering Sea; go south and then float clockwise west towards Hawaii, or not turn at all and head straight on for the coast. The Eos authors speculated that some tub toys could eventually reach the North Atlantic though a combination of ocean water and pack ice transport into the Arctic Sea through the Bering Strait or traverse the Bering Sea and head south towards Japan. Historic examples since the late 19th century of shipwreck debris or planned bottle/container releases support both these long-term travel pathways (http://oceanmotion.org/html/gatheringdata/flotsam.htm).

With additional co-authors, Ebbesmeyer and Ingraham did a follow-up Eos article in January 2, 2007 (http://faculty.wwu.edu/wallin/envr325/tubtoys_ocean_circ.pdf or http://onlinelibrary.wiley.com/doi/10.1029/2007EO010001/pdf) on the toys and other cargo and natural flotsam looking at long-term trajectories. The speed of tub toys travel had eventually decreased, after initial passage to Alaska, due to decreased windage as the toys aged and leaked, barely floating above the surface. Computer simulations were combined with flotsam reports from western Canada and southern Alaska. In that period, the authors found toys had completed up to four round-trips on various sub-orbits of the Subarctic Gyre.
 
Subarctic Gyre and locations of various flotsam releases and finds (Ebbesmeyer and others, 2007).
Flotsam study, of both planned and accidental releases, is the research focus of the Eos articles' lead author, Curtis Ebbesmeyer (http://oceanmotion.org/html/gatheringdata/flotsam.htm). For tracking specific flotsam debris, he uses reports from beachcombers (including beachcombersalert.org which he founded), and solicited information using local media, and beachcomber and lighthouse keeper networks and associations, an example of organized citizen science data collection (another citizen science example: http://app.budburst.org/web/budburst).

So WHY am I discussing PLASTIC in this blog? The current feedstock for plastic is petroleum (mostly in Europe) or natural gas (US manufacture), so it has a natural geologic carbon base. Plastic, and “synthetic” fibers such as rayon or nylon, are synthetic meaning that they are not naturally-occurring organic polymers (long chains of repeating organic units) (http://www.chemheritage.org/discover/online-resources/conflicts-in-chemistry/the-case-of-plastics/all-science-of-plastics.aspx).  Even in its anthropogenically transformed manufactured state, plastic remains part of the global carbon cycle, for better or worse.