Archive for August, 2011

Skidaway Institute scientist studies hydrothermal vents, undersea volcano

August 22, 2011

Skidaway Institute of Oceanography scientist Aron Stubbins joined a research cruise this summer to study hydrothermal vents, but what his fellow scientists found was a recently erupted undersea volcano.

Aron Stubbins

The Axial Seamount is an undersea volcano located about 250 miles off the Oregon coast and is one of the most active and intensely studied seamounts in the world. What makes the event so intriguing is that Bill Chadwick, an Oregon State University geologist, and Scott Nooner, of Columbia University, had forecast the eruption five years before it happened. Their forecast, published in the Journal of Volcanology and Geothermal Research, was based on a series of seafloor pressure measurements that indicated the volcano was inflating and is the first successful forecast of an undersea volcano.

The discovery of the new eruption came on July 28, when Chadwick, Nooner and their colleagues led an expedition to Axial aboard the R/V Atlantis, operated by the Woods Hole Oceanographic Institution. Using “Jason,” a remotely operated robotic vehicle (ROV), they discovered a new lava flow on the seafloor that was not present a year ago. The expedition was funded by the National Science Foundation and the National Oceanic and Atmospheric Administration (NOAA).

“When eruptions like this occur, a huge amount of heat comes out of the seafloor, the chemistry of seafloor hot springs is changed, and pre-existing vent biological communities are destroyed and new ones form,” Chadwick said. “Some species are only found right after eruptions, so it is a unique opportunity to study them.”

Stubbins was on the cruise to study the dissolved organic matter being released from the hydrothermal vents in the ocean floor with Pamela Rossel from the Max Planck Institute Marine Geochemistry group in Oldenburg, Germany, and David Butterfield from the NOAA Vents program. Funding for Stubbins and Rossel was provided by the Hanse-Wissenschaftskolleg (www.h-w-k.de) and Max Planck Institute, both in Germany.

“The material from the vents reaches over 300 degrees centigrade,” Stubbins said.

At that temperature, the heat modifies the dissolved organic matter, altering its chemistry and reactivity, and therefore, its fate in the water column.

“These ecosystems are amazing,” Stubbins continued. “They include large worms, snails, fish and shrimp that live thousands of meters below the ocean. All this life is fueled, not by the sun, but by chemicals released from the vents”

The manipulator arm of the ROV Jason prepares to sample the new lava flow that erupted in April 2011 at Axial Seamount, located off the Oregon coast. (photo courtesy of Bill Chadwick, Oregon State University; copyright Woods Hole Oceanographic Institution)

Immediately after an eruption the whole system is in flux, continued Stubbins. Vents in the ocean floor called snow blower vents produce streams of white particles, creating a snow globe effect. These snow blowers are only short lived.

“Getting samples from these ephemeral systems provided us with a novel opportunity to gain new insight into these deep sea ecosystems” said Stubbins.

For Chadwick and Nooner the eruption was vindication for years of hard work. “The acid test in science – whether or not you understand a process in nature – is to try to predict what will happen based on your observations,” Chadwick said. “We have done this and it is extremely satisfying”

For Stubbins and Rossel, the journey of discovery is just beginning. “Nobody knows how much carbon is pumped into the ocean by these snow blowers or the other vents associated with the eruption” Stubbins said. The good fortune of sampling right after a major eruption has provided a unique opportunity to find out.

Back to Alaska!

August 19, 2011

Hello from Barrow, Alaska! This is Victoria Baylor and Zac Tait, members of the Frischer lab at Skidaway Institute. We are here to collect our final summer season samples and perform some experiments. We arrived safely in Barrow on August 11th after spending most of the 10th traveling and spending a night in Anchorage. The trip is so long, that we had to spend the night in Anchorage AK. We stayed at our usual place, the Holiday Inn Express in Anchorage and enjoyed fine dining at Simon & Seaforts. We have to admit the food was exactly spectacular and with a good nights rest we were ready to head off to Barrow on the 11th.

We made it safely to Barrow and were met by Dylan and Glenn Roy, two of the UMIAQ  Logistics personnel, and Rachel Sipler from the Bronk lab at Virginia Institute of Marine Science (VIMS.) The first thing we noticed as we walked off the plane in Barrow, Alaska was all of the snow and ice was gone. The ice was just beginning to melt on the roads at the end of the last trip in May but now the landscape was transformed into a gravelly, boggy mud-puddle. We left with Rachel, then checked into our hut and were surprised that our entire group plus Karl Newyear , Chief Scientist of UMIAQ, would be occupying the same space. That’s 8 people in one hut…..and only one bathroom.  It was our first group housing experience.

Victoria and the "welcome sign"

After getting settled in, we decided to set-up our labs. We pulled all of our supplies down from storage and distributed them to the Barrow Alaska Research Center (BARC ) lab and the Beach freezer cold room. After setting-up, with no more work to do, we did our grocery shopping and returned home to await the arrival of our other team members. That’s when we received the news that Barrow was out of fuel and we were being asked to reserve our fuel as best as possible. We also received the news that due to high winds we would possibly delay our first sampling trip which was scheduled for Thursday morning.  There were two barges on the way to deliver gas but it was uncertain when the gas would be available.  Not having gas was certainly going to put a damper on our sampling plans by boat so we began to think about other options.

Winds were blowing as high as 25-30kts. Winds like those made usually simple tasks like opening and shutting car doors quite the task. So in light of the weather, all we could do at that point was wait and hope for the best. Part of our summer sample collection involves going 30-40 miles from Barrow to collect water from tundral melt pools that haven’t been influenced by civilization. These melt pools contain organic carbon compounds which we hypothesize will stimulate bacterial activity when released into the coastal ocean.  We usually collect this water by travelling away from town by boat but because of the fuel and weather issues, that wasn’t possible.

On Friday & Saturday, we concentrated our efforts on setting up both our BARC lab for RNA extraction and gear cleaning and the Beach freezer cold room where we’d be filtering water for DNA & RNA collection and Zac’s tundra melt-water incubation studies.  As part of his thesis project, Zac is trying to find out if bacteria will be able to “eat” this material and if they do if it would increase their usage of nitrate. Because nitrate is what limits the productivity of the Arctic Ocean (i.e. how much of the green things at the base of the food web can grow) if bacteria start using more of it this could profoundly affect the food web in the Arctic. If the permafrost (frozen tundra) melts with a warming climate it could mean less fish, seals, bears, birds, and whales.

Things went pretty smoothly with setup. We washed all of our supplies and organized our work spaces.  Then, our group met to discuss sampling options in light of the rough weather. We worked closely to try to create some feasible scenarios that would allow for Zac & Rachel to collect tundra melt-water.  After a meeting with the logistics personnel, the option of using ATV’s to collect the tundra water was presented, but we had to wait to see how things would work out with the weather. So to lift our spirits the group went out to eat delicious Chinese food at Sam and Lee’s and caught a few minutes of the first football game of the season. This also happens to be the highest latitude football game played in the world.  The score at half time was Barrow 35 – Away team 0.

Zac caught chugging down his 3rd bowl of chicken egg drop soup.

 

The Barrow Whalers “Thunder on the Tundra”

By Sunday we got a break in the weather and we were given the green light to go ahead and use the ATV’s to gather tundra water. Rachel, Zac, Lynne, & Marta (Lynn and Marta are also from the Bronk lab at VIMS) all suited up and headed off with Brower to go find some tundra melt-pools.

Our guides for the trip

The  ATV trip was an incredibly a bumpy, yet fun ride. The guide’s idea of a ‘trail’ was simply a general direction across the tundra.   It was hard to compare the terrain on this trip to anything we have encountered. The closest comparison we could think of is: the tundra is like a very rough, frozen ocean, turned to mud. We then rode across this rough landscape at high speeds on ATVs; it was both scary and exhilarating. Needless to say, some ibuprofen and bed-rest were welcomed at the end of that trip. Fortunately, the trip was successful and we were able to get plenty of tundra water containing the high concentration of humic acids that we needed to get our experiments started.

The winds decreased further by Monday so it was decided that we could go on our first sampling trip on the ocean.  At 10 in the morning, we loaded our gear and everyone, with the exception of Victoria  and Marta, headed out. Within 2 hours, the group returned and unfortunately couldn’t go out due to the low tide.  A second attempt was made at 1pm and the boat was launched. While the group was out, the winds picked up again. The decision was made that is was too treacherous to return to the same boat ramp that we left from, so we had to continue around Point Barrow, directly into very high winds and seas to a more sheltered ramp. Several times the boat was airborne after being launched over a 5 or 6 foot swell. We did eventually make it back, but it was a punishing ride. We came back at around 5pm with water samples and told Victoria and Marta about a huge polar bear we’d seen just up on the way back from the boat ramp.

The sampling team (l-r) Rachel, Tara, Lynne, Karie, & Zac

While the group unloaded the boat, Marta and Victoria went to check get some pictures of the Polar Bear. We were later told that there was a serious storm and somehow the polar bear ended up stranded in the ocean and swimming 100nmi to shore. It was huge and completely out of energy after the long swim. We watched the bear, feeling at ease since a bear guide who was armed with a rifle was nearby.  Later, several people from our group witnessed the bear get shot by a local hunter. Rest in peace Polar Bear.

Polar Bear

Back in the Beach freezer cold room, we worked for several hours filtering our waters samples to collect DNA & RNA samples. Zac finally had both humic and seawater to set up his incubations. We worked pretty late but we were quite excited that we were finally able to get samples.

Tuesday was primarily a lab day and we extracted RNA and prepared for the Wednesday’s boat trip.  The other groups worked to process their water samples. We were able to get out again on Wednesday for sampling. So far weather predictions are in our favor and we look forward to having a couple of more sampling trips before the weeks end.

Erosion threatens Coastal Georgia archaeological sites

August 1, 2011

Along the Savannah River in Chatham County are the remains of a large, complex, former rice plantation. Archaeologists may be able to learn much about the life of Georgia’s early inhabitants by studying this site, but only if they hurry. Site 9CH685, as it is known, is threatened by shoreline and tidal creek erosion – the result of the nearby river moving closer to the site every day.

Site 9CH685 is just one of 42 archaeological sites on Georgia’s back barrier islands recently studied by a team from the Skidaway Institute of Oceanography and the Georgia Department of Natural Resources (DNR) Historic Preservation Division. The sites include a range of types, from Native American shell middens to colonial cemeteries and Civil War artillery batteries. The team spent two years studying the erosion and accretion patterns near each site to assist DNR in prioritizing the sites that require the most immediate attention. Funding for the project came from the Georgia Coastal Zone Management Program.

“The Georgia coast is constantly evolving,” said Clark Alexander, the Skidaway Institute scientist who directed the project. “During the past 150 years, the shoreline has moved more than a hundred meters along many parts of the Georgia coast.  The natural forces of wind and water have formed and changed the shape of our coastline over the centuries and continue to do so.”

Typically it is not feasible to preserve sites against these forces, so it is critical to document the sites before they are lost if there is any hope to record the history contained within them.

“Once an archaeological site has been eroded away, it cannot be replaced and the information it contained is lost forever, said Chris McCabe,  deputy state archaeologist for the Georgia Department of Natural Resources (DNR). “The loss of archaeological information to natural processes in our dynamic coastal setting is an ongoing issue for us.”

The team used a combination of current shoreline measurements near the known sites, combined with historical shoreline information from aerial photographs, charts and maps, some dating back to the mid-19th century.

Skidaway Institute's Claudia Venhern uses a highly accurate GPS instrument to record the shoreline of a Georgia coastal island.

It was Skidaway Institute researcher Claudia Venherm’s job to survey the current shoreline. Using an extremely precise GPS receiver, she walked the shorelines measuring the exact location of the high water mark within a few inches. Later, she mapped the shoreline and compared it with the historic data for the same location to determine how fast the shoreline is changing.

“We can use Geographic Information System (GIS) technology to overlay the location of the current shoreline with the shorelines from older photos and maps and obtain a very good picture of what is happening to any piece of coast,” Venherm said.

All the sites were examined to determine which were in the most danger of loss to erosion. The projected life of each site was calculated as the number of years until erosion would destroy the entire site.

Six sites had already been lost to erosion by the time the team visited the coordinates for these sites. Four more sites were still present, but are completely or almost completely submerged at all stages of the tide. The team determined 21 of the sites were eroding, and three of those have a projected life of less than 50 years.

“This study will be a big help to us,” said McCabe. “We can’t stop the erosion, but we can prioritize our work, and maximize the amount of cultural information we obtain before a site is lost.”

That rice plantation site has already yielded clues about the early Georgia economy. The tidal creek threatening the main site has produced several surface artifacts from the late 19th and early 20th centuries. A section of whiteware dinner plate etched with the name “Greenwood China Company”, which designed dinnerware specifically for use aboard coastal steamboats, was found in the creek bed.

“This artifact suggests that materials from maritime vessels had found their way to a group of individuals living at the plantation,” said McCabe. “In addition, an aqua colored bottle embossed with the name ‘Packard & James New York’ was found.”

This merchant firm distributed spices and coffee at the end of the 19th century, and its discovery at a Savannah River site hints at important turn-of-the-century maritime sail and steam trading networks.

These glimpses into the past are fleeting however, as time and tide erase these ephemeral fragments of history.  This study provides the data that the DNR needs to save as much of Georgia’s rich coastal history as possible.