Atlanta Geological Society Newsletter

ODDS AND ENDS Dear AGS members,

I hope you have enjoyed the summer and the eclipse.

It is rare that the totality is so close to where we live.

As we march to fall, I would like to highlight a few

activities for the Society. Sometimes a realization is

just the recognition of the obvious. When we were

working on the revamped website and saw the

picture of the Atlanta skyline, I thought why don’t

we focus a part of our time over the next several

years on Atlanta, Atlanta area and Georgia geology.

There is a new tunnel being drilled in town. Perhaps

someone knows someone who has done the geotech

work on these newer large structures, including the

new stadium? As fascinating as I found the

climate/geology talk by Dr. Cobb, we ought to focus

part of our time on the geology of our home town

and home state.

For many years, as I composed the newsletter, I

would notice that Earth Science Week was in two

weeks and there wasn’t time to participate as an

organization. This year, I can do something about

that. Earth Science Week is October 8-14 and the

theme this year is Earth and Human Activity. There

is a fieldtrip from nearly 10 years ago that examines

the geology and hydrogeology of Lawrenceville

developed by the USGS. I propose we run that field

trip October 14. Its relatively local, using local

resources and ties us into the bigger national

celebration. More in the coming months.

https://www.earthsciweek.org/about-esw Also check

out the coming speakers on Pg. 4.

Ben Bentkowski AGS President

August Meeting

Join us Tuesday, August 29, 2017 at the

Fernbank Museum of Natural History, 760

Clifton Road NE, Atlanta GA. The

meeting/dinner starts at 6:30 pm and the

meeting starts approximately 7 p.m.

This month’s presentation is: “The

Carolina Sandhills of the Southeastern

United States: Eolian Sand Sheets and

Dunes that Were Active During the Last

Glaciation”presenterd by Dr. Chris

Swezey. Please find more information

about Dr. Swezey’s bio on page 4 of the

newsletter.

Please come out, enjoy a bite to eat, the

camaraderie, an interesting presentation and

perhaps some discussion on the importance

of accurate mineral characterization. Also,

the differences that can exist between

mineralogical, industrial and regulatory

definitions for minerals.

Keep up todate with the AGS at:

www.atlantageologicalsociety.org

or at Facebook

facebook.com/Atlanta-Geological-

Society

Page 2 AGS August 2017

This Month’s Atlanta Geological Society Sponsor

AGS August 2017 Page 3

Page 4 AGS August 2017

This Month’s Atlanta Geological Society Speaker

Our Speaker for this coming Tuesday will be Dr. Chris Swezey of the USGS. His current research and presentation

will be on “The Carolina Sandhills of the Southeastern United States: Eolian Sand Sheets and Dunes that Were

Active During the Last Glaciation”. The Carolina Sandhills is a 15 to 60 km wide physiographic region in the

southeastern United States, extending from the western border of Georgia to central North Carolina along the updip

portion of the Coastal Plain province. In Chesterfield County (South Carolina), the “sandhills” occur at ca. 60 to 150

m elevation and in most places consist of <1.5 m thick sand that blankets the landscape, but in areas of higher

elevation the sand forms subdued hills (<7 m relief) with steeper sides on the east and southeast. The “sandhills” are

interpreted as eolian sand sheets and dunes that were active predominantly during the last glaciation. The poor

sorting, coarse grain size, and spatial association with poorly indurated Cretaceous sandstone suggest that the sand

has not traveled far and was derived from the underlying Cretaceous strata.

Dr. Chris Swezey resent Research and Publications:

Research Geologist (2009-Present), U.S. Geological Survey (USGS) Eastern Geology & Paleoclimate Science

Center, Reston, Virginia. I conduct research on the stratigraphy, sedimentology, and geomorphology of the Atlantic

Coastal Plain (USA). This work is focused primarily on basic geologic mapping for understanding the geologic

framework of the Coastal Plain, and characterization of Coastal Plain strata that are major aquifers for water

resources.

Research Geologist (2000-2009), USGS Eastern Energy Resources Team, Reston, Virginia. I conducted

assessments of undiscovered oil and gas resources in the Appalachian, Michigan, and Illinois basins (USA). This

work improved understanding of national energy supplies, provided input for economic analysis of petroleum

resources, and improved understanding of the stratigraphy and petroleum systems of the basins.

Quaternary Research 86 (2016) 271-286

The Carolina Sandhills: Quaternary eolian sand sheets and dunes along the updip margin of the Atlantic Coastal

Plain province, southeastern United States Christopher S. Swezey, Bradley A. Fitzwater b, G. Richard Whittecar,

Shannon A. Mahan, Christopher P. Garrity, Wilma B. Aleman Gonzalez, Kerby M. Dobbs.

Geology and geomorphology of the Carolina Sandhills, Chesterfield County, South Carolina Christopher S. Swezey

U.S. Geological Survey, Bradley A. Fitzwater and G. Richard Whittecar Old Dominion University.

AGS August 2017 Page 5

Continental Patterns of Submarine Groundwater Discharge Reveal

Coastal Vulnerabilities

Abstract

Submarine groundwater discharge (SGD) delivers water and dissolved chemicals from continents to oceans, and its spatial

distribution affects coastal water quality. Unlike rivers, SGD is broadly distributed and relatively difficult to measure,

especially at continental scales. We present spatially resolved estimates of fresh (land-derived) SGD for the contiguous

United States based on historical climate records and high-resolution hydrographic data. Climate controls regional patterns

in fresh SGD, while coastal drainage geometry imparts strong local variability. Because the recharge zones that contribute

fresh SGD are densely populated, the quality and quantity of fresh SGD are both vulnerable to anthropogenic disturbance.

Our analysis unveils hot spots for contaminant discharge to marine waters and saltwater intrusion into coastal aquifers.

Submarine groundwater discharge (SGD) influences global geochemical cycles and coastal water quality by delivering

chemical compounds and dissolved ions from land to sea. SGD includes two primary components: fresh, land-derived

groundwater that infiltrates on land, and salty, ocean-derived groundwater that infiltrates offshore and returns to the sea.

Although small in volume, fresh SGD exports naturally derived elements such as calcium and silicate at rates that rival

those of rivers. Fresh SGD is sensitive to human disturbance, and mixtures of fresh and saline SGD transport nutrients and

other contaminants offshore. Therefore, the spatial distribution of fresh SGD has a direct impact on patterns of coastal

water quality. High rates of nutrient-rich SGD, for example, contribute to harmful algal blooms and hypoxia. SGD patterns

also influence ocean temperature and alkalinity, which are key controls on marine ecological and biogeochemical

processes.

To understand the influence of fresh SGD on biogeochemical cycles and coastal water quality, rate assessments are needed

at global and local scales. However, fresh SGD is difficult and costly to measure, and observations are scarce. Fresh SGD

is heterogeneous and diffuse, unlike river discharge, which is concentrated at discrete and readily measurable points along

the coast. Although many techniques exist to measure fresh SGD, most measurements are focused on a handful of well-

studied, easily accessible locations. The majority of these locations are on the Atlantic coast of the United States (Figure.

1). In the absence of measurements, water budgets have been used to map fresh SGD at high resolution over small coastal

regions and low resolution across the global oceans. These disparate scales of analysis leave critical gaps in our

understanding of SGD. High-resolution estimates are needed across large regions to reveal relationships among climate,

geology, and SGD and to identify where coastal water resources are vulnerable to degradation.

Here, we present high-resolution continental-scale estimates of fresh SGD across the contiguous United States. Our

estimates are based on a simple water budget analysis and state-of-the-art continental-scale hydrography and climate data

sets. Recharge zones, or contributing areas, for fresh SGD are defined with high-resolution hydrographic data. We assume

that recharge zones are the wedge-shaped land areas outside stream catchments where water flows directly to the coast

(Figure. 2, inset). We then assume that recharge across these coastal catchments is the component of precipitation that

infiltrates and would become base flow to a stream, if a stream were present, but instead flows to the coast. This recharge

rate is derived from three decades of reanalysis of climatic data.

To validate our estimates, we compiled 18 local estimates of SGD across the United States. We sought representation from

diverse locations along the Pacific, Gulf, and Atlantic coasts and favored studies that used direct near-shore measurements

to estimate the fresh component of SGD wherever possible. We excluded sea-based measurements using radon or radium

tracer techniques, which can capture a large saline component of SGD. Sea-based measurements sometimes predict

substantially larger SGD rates than near-shore measurements, simulations, and water budget–based estimates. Our

predicted SGD rates are correlated with local estimates but are consistently lower (Figure. 1). The magnitude of

discrepancy shows no apparent relationship with geology, climate, land use, or population density. Some field

measurements may overestimate fresh SGD, because sites are often selected where fresh SGD is likely to be focused (for

example, in permeable sands or bay heads where groundwater flow paths converge). Although field measurements may

Page 6 AGS August 2017

Continental Patterns of Submarine Groundwater Discharge Reveal

Coastal Vulnerabilities (Continued)

overestimate fresh SGD, our approach likely underestimates them because coastal recharge zones could import

groundwater from upland catchments. These potential additional groundwater sources are not included in our analysis.

Furthermore, fresh SGD estimates from water balance approaches tend to decrease with increasing spatial resolution, and

our analysis uses high-resolution hydrography data. The approach nevertheless allows for unprecedented mapping of fresh

SGD.

At the local scale, our analysis exposes a strong heterogeneity in fresh SGD rates (Figure. 2, expanded map). This

heterogeneity can be explained by the variability in land area that contributes groundwater to a given length of coastline.

We define the coastal drainage length, which represents the average distance that groundwater travels from its point of

recharge to the coast (Figure. 2, inset). The drainage length equals the recharge area for fresh SGD divided by the length

of coastline where discharge occurs. It varies strongly with local topography and locations of coastal rivers (Figure. 2,

expanded map). As a result, the spatial variability in fresh SGD over a typical 100-km segment of shoreline is almost as

large as the variability at the continental scale. For example, the coefficient of variation for SGD within 100 km of San

Francisco is 0.76, whereas its coefficient of variation along the entire West Coast is 1.10 (Figure. 2). Because of this

strong local variability, SGD measurements at a single site cannot be extrapolated to other nearby sites with high

confidence. Moreover, human modifications to coastal drainage networks affect patterns of fresh SGD. For example, fresh

SGD rates are low in some areas of Florida with highly altered drainage networks (Figure. S2).

At the continental scale, patterns in fresh SGD depend on both drainage geometry and climate. The influence of climate is

clear along the West Coast from Southern California to Washington (Figure. 2), where net precipitation and fresh SGD

both increase by more than 90%, but coastal drainage length is consistent. Meanwhile, the influence of drainage length is

evident across East and West coasts. For example, net precipitation is similar in the Pacific Northwest and the mid-

Atlantic, but fresh SGD rates are ~50% greater in the Pacific Northwest because of the abundance of long coastal

drainage lengths in steep terrain (Figure. 2 and fig. S1).

At the continental scale, recharge areas for fresh SGD constitute a small portion of the total land area (0.4% of the

contiguous United States). However, these areas drain more water than the continental interior on an areal basis because

Figure. 1 SGD Estimates From This Study and The

Literature.

Our SGD values correlate well with local estimates but

are generally lower. Circles are from seepage meters,

squares are from water budget analysis, and triangles

are from multiple methods. Solid symbols indicate

fresh SGD estimates. Open circles indicate total (fresh

and saline) SGD. We calculated total SGD rates from

our fresh rates using the relation SGDtotal = 1.1 SGDfresh

+ 470 m2/year.

AGS August 2017 Page 7

Continental Patterns of Submarine Groundwater Discharge Reveal

Coastal Vulnerabilities (Continued)

they receive more net precipitation. The total volumetric rate of fresh SGD from the contiguous United States to the

oceans is 15 ± 4 cubic km/year, or <1% of total land runoff. Because this simple water budget analysis may

underestimate fresh SGD by up to 40% (Figure. 1), rates may be as high as 25 ± 7 cubic km/year, or <2% of runoff.

These continental-scale estimates are in line with previous estimates for the contiguous United States [1 to 10% of

runoff] and the world [6% of runoff]. Note that saline SGD is substantially greater than the fresh component estimated

here and may be as large as 300 to 400% of global runoff, but the fresh component is most vulnerable to contamination

and other anthropogenic disturbances. Although volumetrically small, fresh SGD can carry large contaminant mass

loads. For example, in some parts of the world, fresh SGD delivers up to 30 times as much nitrogen to the coast as rivers.

The average volumetric flux of fresh SGD per unit length of coastline is 420 m2/year, but rates span orders of magnitude

(Figure. 3, inset). Although SGD is ubiquitous, concentrated discharge zones contribute the majority of fresh SGD to the

oceans: Half of all fresh SGD is focused along only 14% of the coast. Interestingly, rates of fresh SGD follow a log-

normal distribution (Figure. 3, inset), like permeability values for the shallow earth. Permeability is difficult to measure

because it ranges by orders of magnitude and is scale-dependent. A particular strength of our analysis is that it does not

require permeability data but relies instead on standardized topographic and climatic data sets.

Most of the global population lives near and depends on coastal water resources and fisheries. Thus, high-resolution data

sets are imperative for identifying coastal waters that may be vulnerable to “hidden” contaminant loads from fresh SGD.

Within the contiguous United States, 3% of the population inhabits recharge areas for fresh SGD, which represent only

0.4% of the total land area. Although 72% of recharge areas were undeveloped as of 2011, conversion to agricultural and

urban land use is ongoing. With coastal land development, nutrient loads to groundwater from septic tanks and fertilizers

are increasing. Making matters worse, wetland loss reduces coastal resilience to contaminant loading because wetlands

are efficient contaminant filters. Regions with above-average fresh SGD and land use development are particularly

vulnerable to groundwater-borne contamination, and these regions represent 12% of the coastline. Vulnerable regions

Figure. 2 Map of Fresh SGD Rates

Along the Contiguous United States

Coast.

On the West Coast, fresh SGD increases

from south to north (point A to point B)

with net precipitation (Net P) while

drainage length (DL) remains consistent.

The shape of recharge zones (inset in map)

dictates local variability; recharge zone a

has shorter DL, whereas zone b has longer

DL. Fresh SGD is calculated from the

product of infiltrating precipitation (I) and

DL (DL=A/L, where A is recharge zone

area and L is coastal length).

Noninfiltrating runoff (R) does not

contribute to fresh SGD. Expanded view of

Cape Cod, Massachusetts shows coastal

recharge zones colored by rate of fresh

SGD.

Page 8 AGS August 2017

Continental Patterns of Submarine Groundwater Discharge Reveal

Coastal Vulnerabilities (Continued)

include the northern Gulf Coast from Mississippi to the Florida Panhandle, northern Atlantic Coast, and Pacific Northwest

(Figure. 3). These regions have previously been shown to have high potential nitrogen inputs from SGD to coastal waters.

Vulnerable regions should be monitored for direct nutrient inputs from fresh SGD.

High-resolution maps of SGD are also useful for assessing vulnerability of coastal aquifers to saltwater intrusion (Figure.

3). In populated areas, groundwater extraction subtracts from the recharge available for fresh SGD and can lead to

saltwater intrusion. Most coastal aquifers are more sensitive to groundwater extraction than sea level rise. We predicted

vulnerability to saltwater intrusion using an analytical solution for the position of the freshwater-saltwater interface,

assuming a population-dependent groundwater extraction rate that directly subtracts from the rate of fresh SGD.

Coastlines are considered vulnerable where the toe of the freshwater-saltwater interface reaches the groundwater divide of

the coastal aquifer, which implies imminent and full saltwater intrusion. These regions represent 9% of the coastline and

include confirmed locations of saltwater intrusion such as Long Island, New York and Los Angeles, California (Figure.

3).

Because of the highly heterogeneous nature of fresh SGD, neighboring coastal zones can be vulnerable to saltwater

intrusion and discharge of groundwater-borne contaminants to the ocean. Regions of mixed vulnerability include

southeastern Florida and New Jersey, among many others. Only a small fraction of coastline (<1%) is dually vulnerable to

both saltwater intrusion and offshore contamination, including the heavily developed and populated areas of San

Francisco, Los Angeles, and Long Island (Figure. 3). If these urban areas rely primarily on groundwater to meet their

resource demands, the resulting deductions to fresh SGD may cause full saltwater intrusion. Conversely, effective

groundwater management may sustain fresh SGD rates, but contaminant loads to the coast may be high.

As the resolution of global hydrographic data improves, this same approach can be used to predict global distributions of

fresh SGD and vulnerabilities in coastal water quality. Vulnerable regions will shift and likely grow with coastal land use

change, population growth, climate change, and sea level rise. In many areas, rates of fresh SGD will decrease as

impervious pavement expands and groundwater withdrawals increase. Regions with high rates of fresh SGD that are

currently vulnerable to offshore contamination may instead become vulnerable to saltwater intrusion. Because rates of

fresh SGD are highly heterogeneous, spatial estimates are imperative for identifying monitoring needs and assessing

threats to coastal water quality on both sides of the land-sea boundary, in onshore aquifers and marine surface waters.

http://science.sciencemag.org/content/353/6300/705.full

Figure. 3 Coastal Vulnerability Map.

Vulnerability to offshore contamination (dark

blue) is identified where the rate of fresh SGD is

above average (420 m2/year) and developed or

agricultural land use is above average (27.7%).

Vulnerability to saltwater intrusion (magenta) is

identified where low fresh SGD or high

groundwater extraction may cause complete

saltwater invasion. Light blue areas of coastlines

are vulnerable to both offshore contamination and

saltwater intrusion. Inset shows histogram of fresh

SGD rates for the contiguous United States.

AGS August 2017 Page 9

Much of U.S. Coastline Vulnerable to Hidden Contamination

Most raindrops find their way to the oceans via streams and rivers. But some of them also wind up as a part of a hidden

underground flow that seeps into the ocean through seafloor fissures. When this water, called submarine groundwater

discharge (SGD), trickles through contaminated soil and rock, it can pick up and transport a variety of ions, nutrients, and

chemicals to the sea—including pollutants that contribute to coastal dead zones and toxic algal blooms. Now, a new study

provides the first high-resolution map of the freshwater flow along coastlines in the continental United States, revealing

pollution “hot spots.” The study finds that 12% of the U.S. coastline is particularly vulnerable to contamination, including

parts of the northern Gulf Coast, the Pacific Northwest, and the northern Atlantic coast, where high rates of seepage overlap

areas of human development.

“This freshwater is right underfoot, flowing around leaky gas and septic tanks,” says Audrey Sawyer, a hydrogeologist at The

Ohio State University, Columbus, who led the study.

Typically, researchers don waders or wetsuits to hunt for individual points of groundwater seepage along the coast. They then

use the flows measured at these points as representative of wide stretches of coastline, an extrapolation fraught with

assumptions. Moreover, these hand-collected samples are limited to easily accessible places, such as the shallow, sandy

shorelines of the Atlantic coast. The resulting data are extremely spotty, making it difficult for scientists to accurately predict

the location of seeps, their flow rates, or where pollution will occur, Sawyer says.

Recently, public databases on U.S. rivers, streams, and coastlines have made more sophisticated analyses possible. In the new

paper, Sawyer and colleagues tapped the National Hydrography Dataset, which contains realistic topographic models of

riverbeds, streams, and coastlines across the United States. Combining these models with data on local rainfall and snowmelt,

the team calculated what fraction of the water is carried to the sea by rivers, and what fraction sinks into the ground.

They then focused on the small wedges of coastal land, sandwiched between river drainages, where groundwater drains

directly into the fragile ecosystems near shore. Nationwide, this subterranean flow of freshwater accounts for just 1% to 2% of

total land runoff, according to the study, which is published today in Science. But despite its relatively small volume, fresh

SGD can carry huge contaminant loads, Sawyer notes.

The team found that SGD was highest in places like the Pacific Northwest, where there is both heavy rainfall and steep

topography that leads the groundwater to the ocean. Many of these regions of high SGD—12% of the overall coastline—

overlapped with areas of heavy development, and Sawyer says these areas are the most vulnerable to contamination. “That’s

where we’re growing food, paving cities and towns, and digging septic tanks that leach nutrients and contaminants,” she says.

But extremely low rates of groundwater discharge can also pose a problem. Along the coast of southern California, for

example, low outflows increase the likelihood that saltwater could encroach into an aquifer, particularly as sea levels rise.

That puts local freshwater supplies in danger, Sawyer says. “It really only takes a tiny fraction of saltwater invading

groundwater to render it nonpotable.”

The study can help researchers identify which variables of topography and climate drive submarine groundwater discharge,

says Robert Buddemeier, a geohydrologist at the Kansas Geological Survey in Lawrence. The West Coast’s rocky, steep

terrain, combined with periods of intense rain and drought, makes it intrinsically different from the coastline along the Mid-

Atlantic, which receives steadier rain and slopes more shallowly to the ocean, he says.

A previous attempt to model fresh SGD found flow rates that were an order of magnitude greater than those from the current

study, says Willard Moore, an emeritus professor of geochemistry at the University of South Carolina, Columbia. However,

Moore says the current study is “a big leap” forward, because it uses better topographic and climatic data, and matches well

with 18 localized measurements conducted by other groups.

Page 10 AGS August 2017

Much of U.S. Coastline Vulnerable to Hidden Contamination (Continued)

Sawyer says she hopes researchers and environmental groups will use the new, publicly available database to

identify potential points of contamination in their own communities. Armed with local knowledge of where farms,

paved surfaces, and septic fields may be contributing to toxic runoff, she says, “people will be able to make more

powerful estimates of where risk of contamination might be higher.”

http://www.sciencemag.org/news/2016/08/much-us-coastline-vulnerable-hidden-contamination

The Germans Torpedoed a Ship During World War II. The Wreck is

Now Revealing Secrets About Underwater Mudslides

In 1942, in the midst of World War II, the oil tanker Virginia was anchored off the mouth of the Mississippi River

in the Gulf of Mexico, waiting to unload its cargo in nearby New Orleans. It never made it. Three torpedoes from

a German submarine, the U-507, caused the ship to become engulfed in flames, sinking it and killing 27 of its

crew.

For nearly 60 years, the Virginia rested forgotten on the sea floor. Its vacant decks became decorated with coral

and its portholes housed small fish. Over time, a multibillion-dollar offshore energy industry boomed around it.

Then, in 2001, an oil and gas exploration crew discovered the wreck while using sonar to scan the sea floor. Now,

the Virginia is once again serving as a workhorse: Instead of hauling oil, however, the tanker is helping

archaeologists and geologists understand the Gulf’s underwater mudslides. The sometimes massive slides can

threaten historic wrecks and can cause catastrophic damage to oil pipelines and wells.

In particular, the wreck’s movements over the past 16 years are helping researchers understand how even

relatively modest changes in the weather, not just major events like hurricanes, are reshaping the seafloor.

The Virginia lies on the edge of the Gulf’s continental shelf, in about 200 meters of water just off the Louisiana

coast. It’s a hot spot for underwater mudslides, according to geologist Sam Bentley of Louisiana State

University (LSU) in Baton Rouge, because the Mississippi River deposits large amounts of loose sediment in the

area. The sediments build up over time, forming giant lobes that can break apart and slide down the shelf.

Such slides worry regulators and the oil and gas industry for at least two reasons. One is they cause sediment to

slip from beneath seafloor pipes, leaving them suspended in the water and more vulnerable to breaks. The other

is that the slides—which can be 30 meters thick—can shear through pipelines and other infrastructure. In 2004,

for example, Hurricane Ivan triggered a mudslide that violently damaged 16 oil wells and created leaks.

The wreck’s discovery has provided geologists with some unexpected insight into how fast these lobes can

move. In 2006, archaeologists with the federal government—which manages areas more than 5 kilometers

offshore—set out to survey the Virginia. What they found mystified them: the 10,000-ton wreck had moved 370

meters seaward from its location in a 2004 mapping effort.

The likely cause, the researchers believed, was hurricanes that violently stormed through the Gulf in 2004 and

2005. Geologists knew that severe storms create large waves that, in turn, produce pressure differences on the

sea floor. This buffeting causes naturally occurring methane bubbles in the seabed sediments to contact and

expand, liquefying the mud around them. The process unleashes mudslides—which can carry even a 150-meter-

AGS August 2017 Page 11

The Germans Torpedoed a Ship During World War II. The Wreck is

Now Revealing Secrets About Underwater Mudslides (Continued)

long wreck along for the ride.

In 2017, when another team of researchers from the U.S. Geological Survey (USGS) returned to survey the wreck,

they found it had moved an additional 60 meters seaward. Again, the scientists puzzled: This time, there had been

no major storms to propel the movement.

A recent study led by LSU’s Bentley might explain what is happening. In 2012, the federal Bureau of Ocean

Energy Management (BOEM), which oversees offshore oil operations in federal waters, funded Bentley and

researchers at the USGS to study mudslides in a 100-square-kilometer section near the Mississippi delta, which is

dotted with numerous oil and gas wells and crisscrossed by pipelines.

The team mapped potential mudslide hotspots, extracted 9-meter-long cores from the sea floor, and measured

movements of ocean floor sediments. They also examined weather and other records to see what might be driving

sediment movements in the absence of hurricanes or other major storms.

One conclusion: Masses of cold air that regularly move over the gulf in the winter can stir up waves and pressure

differences that can help push the sediment seawards at rates of up to a meter per year. The cold fronts could help

explain the Virginia’s recent movements, Bentley says. “It would have to be something less energetic than a

hurricane that was causing [the movement], so the next thing down from that are winter cold fronts.”

The findings have implication for both efforts to prevent oil spills and to protect historic wrecks. Under federal

law, offshore oil and gas companies are required to protect cultural artifacts from industrial operations. In the

Virginia’s case, for example, BOEM barred companies from drilling, running pipelines, or dropping anchors

within 300 meters of the wreck. But a moving wreck complicates industry efforts to stay out of that buffer zone.

The rusting hulk could also pose a substantial threat to pipelines or other infrastructure that was originally far

downslope. Luckily, researchers say there are no pipelines in the immediate vicinity of Virginia.

A sonar image of the wreck of

the Virginia, an oil tanker that

was torpedoed by a German

submarine in the Gulf of

Mexico during World War II.

Page 12 AGS August 2017

The Germans Torpedoed a Ship During World War II. The Wreck is

Now Revealing Secrets About Underwater Mudslides (Continued)

Researchers note, however, that there haven’t been systematic surveys of wrecks or slides in the Gulf of Mexico

since the 1970s, so there could be unknown threats sitting in the deep. To fill that knowledge gap, Bentley is

hoping BOEM will support expanding his mudslide study to a larger area covering some 2000 square

kilometers. And archaeologist Douglas Jones, who works out of BOEM’s office in New Orleans, Louisiana, is

proposing a study that would identify other wrecks in slide-prone areas.

In the meantime, researchers plan to keep an eye on the Virginia, which they say has opened a door to better

understanding the complexity and instability of the Gulf’s sea floor. Where the wreck will go next, they say, will

depend on the natural forces that can be difficult to predict.

http://www.sciencemag.org/news/2017/08/germans-torpedoed-ship-during-world-war-ii-wreck-now-revealing-secrets-about-submarine

'Frankenstein Dinosaur' Mystery Solved

Scientists have solved the puzzle of the so-called "Frankenstein dinosaur", which seems to consist of body

parts from unrelated species. A new study suggests that it is in fact the missing link between plant-eating

dinosaurs, such as Stegosaurus, and carnivorous dinosaurs, like T. rex. The finding provides fresh insight on the

evolution of the group of dinos known as the ornithischians. The study is published in the Royal Society journal

Biology Letters.

Matthew Baron, a PhD student at Cambridge University, told BBC News that his assessment indicated that the

Frankenstein dinosaur was one of the very first ornithischians, a group that included familiar beasts such as the

horned Triceratops, and Stegosaurus which sported an array of bony plates along its back. "We had absolutely

no idea how the ornithischian body plan started to develop because they look so different to all the other

dinosaurs. They have so many unusual features," the Cambridge scientist said.

"In the 130 years since the ornithischian group was first recognised, we have never had any concept of how the

first ones could have looked until now." The Frankenstein dinosaur, more properly called Chilesaurus, puzzled

experts when it was first discovered two years ago. It had the legs of an animal like a Brontosaurus, the hips of a

Stegosaurus, and the arms and body of an animal like Tyrannosaurus rex. Scientists simply did not know where

it fitted in the dino family tree. In the currently accepted family tree, the ornithischian group was always thought

to be completely unrelated to all of the other dinosaurs. Palaeontologists regarded these creatures as an odd-ball

group. But a reassessment by Mr Baron published in March in the journal Nature indicated that ornithischians

were more closely related to the meat-eaters, such as T.rex, than previously thought. And it is in re-configuring

the dinosaur family tree that Mr Baron transforms the Frankenstein dinosaur from an enigma into a missing link.

"Now that we think ornithischians and meat-eating dinosaurs such as Tyrannosaurus are related, Chilesaurus

slots exactly in between the two groups. It is a perfect half-and-half mix. So, suddenly in the new tree it makes a

whole lot of sense." The alternative version of the dinosaur family tree, now called the "Baron tree", is more

than just a rearrangement, however. It sheds new light on how different groups of dinosaurs split from one

another and evolved along different paths, adds co-author Prof Paul Barrett from London's Natural History

Museum.

AGS August 2017 Page 13

'Frankenstein Dinosaur' Mystery Solved (Continued)

"Chilesaurus is there at the beginning of one of these big splits and hopefully by understanding more about its

biology it will tell us what the driving factors might have been." Prof Barrett and Mr Baron both believe that

their re-configured tree could well replace the current dinosaur family tree which has stood the test of time for

more than 130 years. The Baron tree is controversial and has its critics. But if it provides further instances where

it can smooth the relationships between different dinosaur groups then its supporters will grow. Mr Baron thinks

the rescuing of Chilesaurus from its Frankenstein status could be just the first of a series reappraisals.

"We've landed a good punch against the counter argument here. This is a very good step towards my main

objective which is to try to really nail down the ornithischian lineage because I think we've been completely

misunderstanding and ignoring this very important group for far too long. "Eventually, we'll arrive at a

consensus. I think this is a step toward the right model."

Prof Sarah Gabbott, from Leicester University, was not involved in the study. She described the new analysis as

"incredibly important". "This is one of those rare fossil discoveries that provides much more evidence to unravel

dinosaur relationships than your average skeleton," she said. "This is because Chilesaurus preserves an unusual

suite of characteristics that are a mix between between the ornithischians and theropods. In particular, its

melange of features helps to reveal the sequence of events during the critical early stages of ornithischian

evolution."

http://www.bbc.com/news/science-environment-40890714

Page 14 AGS August 2017

Scientists Discover 91 Volcanoes Below Antarctic Ice Sheet

This is in addition to 47 already known about and eruption would melt more ice in region affected by climate

change. Scientists have uncovered the largest volcanic region on Earth – two kilometres below the surface of the

vast ice sheet that covers west Antarctica.

The project, by Edinburgh University researchers, has revealed almost 100 volcanoes – with the highest as tall as

the Eiger, which stands at almost 4,000 metres in Switzerland. Geologists say this huge region is likely to dwarf

that of east Africa’s volcanic ridge, currently rated the densest concentration of volcanoes in the world.

Volcanic eruptions may not reach the surface but could melt the ice from beneath and drastically destabilise

itAnd the activity of this range could have worrying consequences, they have warned. “If one of these volcanoes

were to erupt it could further destabilise west Antarctica’s ice sheets,” said glacier expert Robert Bingham, one

of the paper’s authors. “Anything that causes the melting of ice – which an eruption certainly would – is likely to

speed up the flow of ice into the sea.

“The big question is: how active are these volcanoes? That is something we need to determine as quickly as

possible.” The Edinburgh volcano survey, reported in the Geological Society’s special publications series,

involved studying the underside of the west Antarctica ice sheet for hidden peaks of basalt rock similar to those

produced by the region’s other volcanoes. Their tips actually lie above the ice and have been spotted by polar

explorers over the past century.

But how many lie below the ice? This question was originally asked by the team’s youngest member, Max Van

Wyk de Vries, an undergraduate at the university’s school of geosciences and a self-confessed volcano fanatic.

He set up the project with the help of Bingham. Their study involved analysing measurements made by previous

surveys, which involved the use of ice-penetrating radar, carried either by planes or land vehicles, to survey

strips of the west Antarctic ice. The results were then compared with satellite and database records and

geological information from other aerial surveys. “Essentially, we were looking for evidence of volcanic cones

sticking up into the ice,” Bingham said.

After the team had collated the results, it reported a staggering 91 previously unknown volcanoes, adding to the

47 others that had been discovered over the previous century of exploring the region.

These newly discovered volcanoes range in height from 100 to 3,850 metres. All are covered in ice, which

sometimes lies in layers that are more than 4km thick in the region. These active peaks are concentrated in a

region known as the west Antarctic rift system, which stretches 3,500km from Antarctica’s Ross ice shelf to the

Antarctic peninsula.

“We were amazed,” Bingham said. “We had not expected to find anything like that number. We have almost

trebled the number of volcanoes known to exist in west Antarctica. We also suspect there are even more on the

bed of the sea that lies under the Ross ice shelf, so that I think it is very likely this region will turn out to be the

densest region of volcanoes in the world, greater even than east Africa, where mounts Nyiragongo, Kilimanjaro,

Longonot and all the other active volcanoes are concentrated.”

The discovery is particularly important because the activity of these volcanoes could have crucial implications for

the rest of the planet. If one erupts, it could further destabilise some of the region’s ice sheets, which have already

been affected by global warming. Meltwater outflows into the Antarctic ocean could trigger sea level rises. “We

just don’t know about how active these volcanoes have been in the past,” Bingham said.

However, he pointed to one alarming trend: “The most volcanism that is going in the world at present is in

regions that have only recently lost their glacier covering – after the end of the last ice age. These places include

AGS August 2017 Page 15

Scientists Discover 91 Volcanoes Below Antarctic Ice Sheet

However, he pointed to one alarming trend: “The most volcanism that is going in the world at present is in

regions that have only recently lost their glacier covering – after the end of the last ice age. These places include

Iceland and Alaska.

“Theory suggests that this is occurring because, without ice sheets on top of them, there is a release of pressure

on the regions’ volcanoes and they become more active.”

And this could happen in west Antarctica, where significant warming in the region caused by climate change

has begun to affect its ice sheets. If they are reduced significantly, this could release pressure on the volcanoes

that lie below and lead to eruptions that could further destabilise the ice sheets and enhance sea level rises that

are already affecting our oceans.

“It is something we will have to watch closely,” Bingham said.

https://www.theguardian.com/world/2017/aug/12/scientists-discover-91-volcanos-antarctica

2017 Total Solar Eclipse – Phases to Totality

http://www.skyandtelescope.com/astronomy-news/best-2017-solar-eclipse-pictures-from-our-readers/

Page 16 AGS August 2017

August AGS PG Workshop Announcement

Date: August 26, 2017 Time: 10:00am to 12:00pm

Venue: Fernbank Science Center Annex

Speaker: Benjamin Black, PG

Subject: Engineering Geology

The class will cover Soil Mechanics and Soil Strength Testing (Laboratory and Field Methods), Geologic

Hazards (Slope Stability, Earthquakes, etc.), Engineering Geological Mapping, and Site Investigation.

Ben Principal Engineering Geologist for Oasis Consulting Services and has eighteen years experience in

hydrogeological analysis and geotechnical assessment and analysis. He is a registered Professional Geologist

in six states, and is experienced in a wide variety of geotechnical subsurface investigation methods, including

geophysical surveys, geotechnical soil borings, and coring of various types of soft and hard rock. In

particular, he is experienced with the assessment and analysis of rock mass strength with application to slope

stability and engineered structures.

Ben is experienced in shallow and deep foundation design including piles and drilled shafts, slope stability

analysis and stabilization techniques, seepage analysis, excavation design and materials handling, tunnel

design and construction, surveying, and ground reinforcing techniques. He has conducted slope stability

analysis for open pit mines and transportation corridors. He has been responsible for processing and

interpretation of rock mass properties, joint frequencies, selection of design sections, and other pertinent

data. He developed a stability model and performed all calculations necessary to determine factor of safety

and recommendations for slope stabilization for both planar and wedge failure modes.

Ben has worked on U.S. Army Corps of Engineers projects in New Orleans, Louisiana and Miami,

Florida. These projects include levee and deep foundation assessment and design in soft sediments and

statistical analysis based on load and resistance factor design.

Please join us and feel free to forward this announcement to anyone that might be interested. Engineering

geology is well covered on the licensure exams.

Two Professional Development Hours will be offered and everyone is invited to attend. AGS Membership is

not required, but certainly encouraged. An application is attached. More info

at: www.atlantageologicalsociety.org

Thanks,

Ken Simonton, P.G.

kws876@gmail.com

Ginny Mauldin-Kinney, P.G.

ginny.mauldin@gmail.com

Atlanta Geological Society

Professional Registration/Career Development Committee

AGS August 2017 Page 17

Fernbank Events & Activities

Treetop Tales Saturday, August 26, 2017 A new program for preschool through

elementary-aged children featuring

story time and a special activity.

Learn more

Fernbank Forest Native Plant Tour Saturday, September 16, 2017 Gain a better understanding of the native

plant and tree species of Fernbank Forest.

Learn more

FAD: Night at the Science Fair Friday, September 8, 2017 Enjoy playful science experiments you

can do on your own or as a team.

Learn more

Wild Explorer Day Saturday, September 16, 2017 Join the celebration of the 1st anniversary

of WildWoods with a day of nature-

themed fun.

Learn more

Page 18 AGS August 2017

Wildwoods and Fernbank Forest WildWoods features 10 acres of lush woodlands,

highlighted by hands-on exhibits for all ages, tree

pods suspended in the canopy, a nature gallery,

immersive adventures, and meandering trails

emphasizing dramatic slopes and stunning

views. This interpretive nature experience serves as

the new entrance into Fernbank Forest.

Learn more

Titans of the Ice Age On view June 17 – August 27, 2017 Take an unforgettable journey back in time to the

otherworldly frozen landscapes of the northern hemisphere

10,000 years before modern civilization. Titans of the Ice

Age 2D brings this harsh and beautiful era to life—a world

buried in our ancestral memory, populated by saber-tooth

cats, giant sloths, dire wolves and the iconic woolly

mammoths. Travel across monumental glaciers and

sweeping grasslands, rich in life. Roam the mammoth

steppe with baby Lyuba, a female Woolly Mammoth calf

recently exposed by the melting Siberian permafrost, now

one of the best preserved mammoth mummies in the world.

AGS August 2017 Page 19

Now showing in the Fernbank IMAX movie theater:

Mammoths and Mastodons June 17 – August 27, 2017 Journey back in time millions of years ago when mammoths and mastodons roamed the earth. Explore how mammoths and

mastodons lived with other giant creatures like short-faced bears and saber-toothed cats. Joust with mammoth tusks. Touch

the teeth of the colossal mastodon, and feel mammoth fur between your fingertips. Create your own cave art and learn why

early humans both hunted and honored these majestic animals. Live among these larger than life creatures for a day, in the

most captivating, interactive exhibition since the Ice Age.

Amazon Adventure 3D May 20 – September 29, 2017 Experience the epic, true story of explorer Henry Bates' fascinating 11-year journey through the Amazon rainforest as a

young man working to unravel a great scientific mystery. As in any great detective story, audiences will experience the

compelling clues Bates unearths in his major discovery of the phenomenon of “Batesian” mimicry, whereby certain

animals adopt the look of others and thus can deceive predators and prey. Little known to the public, Bates made other

crucial contributions to biology: identifying 8,000 species new to science and most importantly, putting the first ever case

for the creation of a new species, which Charles Darwin called the “beautiful proof” for Natural Selection. See mind-

boggling examples of camouflage and mimicry in the visually stunning and biodiverse Amazon. You’ll be inspired by

Bates' endless curiosity and determination to explore the wilds of nature.

Fernbank Museum of Natural History (All programs require reservations, including free programs)

Page 20 AGS August 2017

AGS Committees

AGS Publications: Open

Career Networking/Advertising: Todd Roach

Phone (770) 242-9040, Fax (770) 242-8388

tdr@piedmontdrilling.com

Continuing Education: Open

Fernbank Liaison: Kaden Borseth

Phone (404) 929-6342

Kaden.Borseth@FernbankMuseum.org

Field Trips: Open

Georgia PG Registration: Ken Simonton

Phone: 404-825-3439

kws876@gmail.com

Ginny Mauldin-Kenney,

ginny.mauldin@gmailcom

Teacher Grants: Bill Waggener

Phone (404)354-8752

waggener80@yahoo.com

Hospitality: John Salvino, P.G.

johnsalvino@bellsouth.net

Membership: Burton Dixon

Dixonburton1@gmail.com

Social Media Coordinator: Carina O’Bara

carina_do@yahoo.com

Newsletter Editor: James Ferreira

Phone (508) 878-0980

ferreira.02767@gmail.com

Web Master: Ken Simonton

kws876@gmail.com

www.atlantageologicalsociety.org

AGS 2017 Meeting Dates

Listed below are the planned meeting

dates for 2017. Please mark your calendar

and make plans to attend.

2017 Meeting Schedule

August 29

September 26

October 31

November 28

December 26

PG Study Group meetings Contact Ken Simonton for the details.

August 26

September 30

October 28

November 25

December 23

AGS Officers

President: Ben Bentkowski

bbentkow@gmail.com

Phone (770) 296-2529

Vice-President: Steven Stokowski

sstokowski@tecservices.com

Secretary: Rob White

Phone (770) 891-0519

robeth@bellsouth.net

Treasurer: John Salvino, P.G.

Phone: 678-237-7329

johnsalvino@bellsouth.net

Past President

Shannon Star George

shannonsgeorge@gmail.com

AGS August 2017 Page 21

ATLANTA GEOLOGICAL SOCIETY

www.atlantageologicalsociety.org

ANNUAL MEMBERSHIP FORM

Please print the required details and check the appropriate membership box.

DATE:_____________________________________________

NAME:____________________________________________

ORGANIZATION:____________________________________________________________

TELEPHONE (1): TELEPHONE (2):

EMAIL (1): EMAIL (2):

STUDENT $10

PROFESSIONAL MEMBERSHIP $25

CORPORATE MEMBERSHIP $100 (Includes 4 professional members, please list names and emails below)

NAME: EMAIL:

NAME: EMAIL:

NAME: EMAIL:

NAME: EMAIL:

For further details, contact the AGS Treasurer:

John Salvino johnsalvino@bellsouth.net

Please make checks payable to the “Atlanta Geological Society” and bring them to the next meeting or remit

with the completed form to:

Atlanta Geological Society, Attn: John Salvino

3073 Lexington Avenue

Woodstock, Georgia 30189

To pay electronically; click

https://squareup.com/store/atlanta-geological-society

CASH CHECK (CHECK NUMBER:___________)