Friday, June 1, 2018

Why am I a vegetarian?

This question comes up all the time.  Being raised in BBQ country of Arkansas, I never met a vegetarian growing up and, like all kids, I fell into doing just what my parents and friends did: eat meat and lots of it. 

But part of growing up is rethinking the ways of our parents, making reasoned decisions on how we want to live our lives. In the late 1990s I met Dolores Proubasta, then Assistant Editor of SEG's Leading Edge magazine and a vegetarian. My thinking on this subject lead to an understanding that meat was fundamentally cruel and unnecessary for nutrition. In August 1998 at an SEG Board meeting in Kananaskis near Calgary, I stood in line for the BBQ and made the decision not to eat meat that day, and have not eaten it any day since. So in August 2018, I will have been an ethical vegetarian for 20 years.

I recall, however, meeting a family of climate vegetarians a few years ago and it took me a while to understand what this is about. Since then, I have done some deep study on greenhouse gasses and animal agriculture. But it turns out (see article below from today's Guardian newspaper) that animal agriculture is an assault not just on climate, but land use and biodiversity.

The food animal industry is unimaginably cruel. Very little has changed since Upton Sinclair's The Jungle was written in 1906, except the accelerating application of perverted science to the design, rearing and killing of food animals. I am still comfortable as an ethical vegetarian, but the new study reported below makes the case for much broader concerns.

Einstein said it best: Nothing will benefit health or increase chances of survival on earth as much as the evolution to a vegetarian diet.


Avoiding meat and dairy is ‘single biggest way’ to reduce your impact on Earth

Biggest analysis to date reveals huge footprint of livestock - it provides just 18% of calories but takes up 83% of farmland

Avoiding meat and dairy products is the single biggest way to reduce your environmental impact on the planet, according to the scientists behind the most comprehensive analysis to date of the damage farming does to the planet.

The new research shows that without meat and dairy consumption, global farmland use could be reduced by more than 75% – an area equivalent to the US, China, European Union and Australia combined – and still feed the world. Loss of wild areas to agriculture is the leading cause of the current mass extinction of wildlife.

The new analysis shows that while meat and dairy provide just 18% of calories and 37% of protein, it uses the vast majority – 83% – of farmland and produces 60% of agriculture’s greenhouse gas emissions. Other recent research shows 86% of all land mammals are now livestock or humans. The scientists also found that even the very lowest impact meat and dairy products still cause much more environmental harm than the least sustainable vegetable and cereal growing.

The study, published in the journal Science, created a huge dataset based on almost 40,000 farms in 119 countries and covering 40 food products that represent 90% of all that is eaten. It assessed the full impact of these foods, from farm to fork, on land use, climate change emissions, freshwater use and water pollution (eutrophication) and air pollution (acidification).

“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” said Joseph Poore, at the University of Oxford, UK, who led the research. “It is far bigger than cutting down on your flights or buying an electric car,” he said, as these only cut greenhouse gas emissions.
“Agriculture is a sector that spans all the multitude of environmental problems,” he said. “Really it is animal products that are responsible for so much of this. Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy.”
The analysis also revealed a huge variability between different ways of producing the same food. For example, beef cattle raised on deforested land result in 12 times more greenhouse gases and use 50 times more land than those grazing rich natural pasture. But the comparison of beef with plant protein such as peas is stark, with even the lowest impact beef responsible for six times more greenhouse gases and 36 times more land. 

The large variability in environmental impact from different farms does present an opportunity for reducing the harm, Poore said, without needing the global population to become vegan. If the most harmful half of meat and dairy production was replaced by plant-based food, this still delivers about two-thirds of the benefits of getting rid of all meat and dairy production.

Cutting the environmental impact of farming is not easy, Poore warned: “There are over 570m farms all of which need slightly different ways to reduce their impact. It is an [environmental] challenge like no other sector of the economy.” But he said at least $500bn is spent every year on agricultural subsidies, and probably much more: “There is a lot of money there to do something really good with.” 

Labels that reveal the impact of products would be a good start, so consumers could choose the least damaging options, he said, but subsidies for sustainable and healthy foods and taxes on meat and dairy will probably also be necessary. 

One surprise from the work was the large impact of freshwater fish farming, which provides two-thirds of such fish in Asia and 96% in Europe, and was thought to be relatively environmentally friendly. “You get all these fish depositing excreta and unconsumed feed down to the bottom of the pond, where there is barely any oxygen, making it the perfect environment for methane production,” a potent greenhouse gas, Poore said.

The research also found grass-fed beef, thought to be relatively low impact, was still responsible for much higher impacts than plant-based food. “Converting grass into [meat] is like converting coal to energy. It comes with an immense cost in emissions,” Poore said.

The new research has received strong praise from other food experts. Prof Gidon Eshel, at Bard College, US, said: “I was awestruck. It is really important, sound, ambitious, revealing and beautifully done.” 

He said previous work on quantifying farming’s impacts, including his own, had taken a top-down approach using national level data, but the new work used a bottom-up approach, with farm-by-farm data. “It is very reassuring to see they yield essentially the same results. But the new work has very many important details that are profoundly revealing.”

Prof Tim Benton, at the University of Leeds, UK, said: “This is an immensely useful study. It brings together a huge amount of data and that makes its conclusions much more robust. The way we produce food, consume and waste food is unsustainable from a planetary perspective. Given the global obesity crisis, changing diets – eating less livestock produce and more vegetables and fruit – has the potential to make both us and the planet healthier.”

Dr Peter Alexander, at the University of Edinburgh, UK, was also impressed but noted: “There may be environmental benefits, eg for biodiversity, from sustainably managed grazing and increasing animal product consumption may improve nutrition for some of the poorest globally. My personal opinion is we should interpret these results not as the need to become vegan overnight, but rather to moderate our [meat] consumption.”

Poore said: “The reason I started this project was to understand if there were sustainable animal producers out there. But I have stopped consuming animal products over the last four years of this project. These impacts are not necessary to sustain our current way of life. The question is how much can we reduce them and the answer is a lot.”

Wednesday, May 16, 2018

AAPG Annual Meeting 2018

Presentations (speaker underlined):

Monday, 10:50-11:10 am, Ballroom A
Seismic Characterization of Natural Fractures in the Buda Limestone of Zavala County, Texas 
A. Smirnov and C.L. Liner

The Buda Limestone is a naturally fractured Early Cretaceous carbonate formation in south Texas which is unconformably overlain by the Eagle Ford Shale. Matrix porosity of the Buda is less than 6%, therefore natural fractures improve the potential for commercial hydrocarbon production from this tight limestone formation. It is a challenge for producers to identify these zones using well log and poststack 3D seismic data which typically available to medium or small exploration companies. This project provides a workflow based on well log analysis tied to seismic acoustic impedance (AI) inversion to locate areas of probable natural fractures.

Acoustic impedance inversion was performed across a 40 square mile 3D seismic survey. The AI data shows low impedance shadow zones on the down thrown side of faults. Post stack geometric seismic attributes such as coherence, maximum and minimum curvature were analyzed in the anomalous AI areas, along with physical seismic attributes such as RMS amplitude and instantaneous frequency.

To map primary porosity, a relationship between acoustic impedance and porosity is established by crossplotting well log data. A linear fit to the Buda data in one well indicates a robust correlation between sonic porosity, density-porosity and AI. Sonic porosity is an indicator of the matrix porosity in the Buda Limestone, while density porosity represents both matrix and fracture porosity. Using the trend line equation for AI vs sonic porosity, the 3D seismic impedance volume was scaled to a matrix porosity volume.

In the downthrown faulted areas, the porosity volume indicates values greater than expected of matrix porosity. This has been reported elsewhere in carbonate reservoirs as an indicator of enhanced secondary (fracture) porosity. This study indicates that a combination of acoustic impedance inversion and seismic attributes can identify areas of enhanced natural fracturing within the Buda Limestone interval.

Tuesday, 9am, Exhibit Hall
Mapping Lower Austin Chalk Primary and Secondary Porosity Using Modern 3-D Seismic and Well Log Methods in Zavala County, Texas [poster 77]
D. Kilcoyne and C.L. Liner

Establishing fracture distribution and porosity trends is key to successful well design. The Austin Chalk has historically been referred to as an unpredictable producer due to high fracture concentration and lateral variation in stratigraphy, however recent drilling activity targeting the lower Austin Chalk has been very successful. The Upper Cretaceous Austin Chalk (AC) and Eagle Ford (EF) units are considered by many to act as a single hydrocarbon system so both units are investigated. Communication between these two units is largely through expulsion or dewatering fractures, extensional faults or along the AC/EF unconformity. Total porosity for the Eagle Ford is composed of a primary matrix component and secondary fracture porosity. For the Austin Chalk, the secondary porosity includes both dissolution and fracture components which complicate wireline and seismic interpretation.

The current study interprets 40 square miles of modern 3D seismic data for horizons and faults using amplitude, coherence and ant tracking seismic attributes. Post stack acoustic impedance (AI) inversion is applied to the time migrated seismic volume with control from two wells; this input data is similar to that available to independent operators active in the area. Wireline acoustic impedance plotted against density-porosity reveal strong correlations that allow calibration of seismic AI into primary, secondary and total porosity from which time slices and surface maps are created. Relationships are identified between porosity and geological features of interest, such as faulted and brittle zones, that may prove useful in guiding future well development in the lower Austin Chalk.

Wednesday, 11:10-11:30 am, Ballroom C
Tracks, Outrunner Blocks, and Barrier Scours: 3-D Seismic Interpretation of a Mass Transport Deposit in the Deepwater Taranaki Basin of New Zealand 
F.J. Rusconi, T.A. McGilvery and C.L. Liner

A series of Plio-Pleistocene mass transport deposits (MTD) have been identified in the deepwater Taranaki Basin, in New Zealand, using the Romney 3D seismic survey. One of these MTDs has been chosen for description and interpretation based on high confidence mapping of its boundary surfaces. The deposit exhibits an array of interesting features similar to those documented by researchers elsewhere plus a unique basal feature unlike those previously observed. The basal shear surface exhibits erosional features such as grooves, “monkey fingers”, and glide tracks. We have been able to image outrunner blocks at the end of the glide tracks in distal areas of the deposit. 

Internally, the MTD is typically characterized by low impedance, chaotic, semi-transparent reflectors surrounding isolated coherent packages of seismic facies interpreted as intact blocks rafted within the mass transport complex. These transported blocks scale up to 1 km wide and 200 m high, and commonly protrude above the upper surface of the flow. This yields a very irregular paleo-bathymetric surface on the top of this and other MTDs with local relief attributed these protrusions ranging from 10 m to >100 m . The complexity of this upper surface had local impact on subsequent flows. 

The term “shield block” refers to those large protruding obstacles on the paleo-seafloor that acted as barriers to subsequent flows as they advanced downslope. Obstacles such as mud volcanos have been documented to act as such barriers resulting in elongate, downflow erosional remnants as positive features. The opposite is the case for shield blocks, which disrupt flow and result in elongate, downflow erosional troughs that are negative features. These local erosional features are then infilled similar to mega flutes and are preserved as elongate isochron thicks on the downflow end of the underlying shield block. Kinematic evidence provided by various structures suggests that the MTD flow direction was SE-NW toward bathyal depths. The features presented and the absence of extensional headwall structures, such as local arcuate glide planes and rotated slide blocks, suggests that this part of the deposit belongs to the translational to distal domain of the MTD, and its source area is expected to be somewhere toward the SE in a paleo continental slope.

Wednesday, May 9, 2018

Hime Honors Thesis 2018

Title page of the thesis.
Link to PDF
A short note was posted to LinkedIn: "My first Honors student at the University of Arkansas is Regan Hime. Double major in Geology/Physics and fantastic GPA. Her Honors thesis was on seismic clinoform scaling laws and she will graduate Summa Cum Laude this week". Post analytics show over 7000 views.