WASHINGTON – Deep beneath the ocean floor off the New Jersey coast lie secrets that could help scientists predict how global warming could impact one of the most popular shorelines in the country.
Gregory Mountain, with a name that befits his expertise, teaches earth and planetary sciences and has spent a lot of time in recent years sailing those waters to uncover the answers.
“This [research] is now to understand better what the future is going to hold,” Mountain said. “The future that is within our grandchildren’s time.”
The Rutgers University professor will set sail again in June, armed with the latest in three-dimensional imaging equipment to capture cross-sectional pictures of the ocean floor. Like tree rings, the layers of sediment provide a history of the Jersey shoreline.
Buried in the sand for thousands of year, the data could offer a glimpse of what rising sea levels caused by the heating up of the ocean, as well as the warming on shore, could mean for the coastline.
Think of it this way, Mountain said: The route of the Garden State Parkway, which in many areas runs close to the coast, was underwater 125,000 years go. Over the next 100,000 years the shoreline has extended out to sea, going so far as to expose the continental shelf.
But in the last 20,000 years, merely a hiccup in geologic time, the Jersey shore has returned 75 miles inland to its present location.
“That’s a very fast retreat and a very fast advance,” Mountain said. “The warming of the planet is now accelerating that change.”
The research has triggered some controversy, however. The research ship will use air guns and a complex series of microphones to create the images of the ocean floor. Mountain and a team of scientists from Rutgers and the University of Texas in Austin, with funding from the National Science Foundation, will trail the air guns attached to long hoses off the back of the research ship.
Environmental groups have expressed concerns about the impact on sea life. The guns will shoot compressed air at specified intervals towards the ocean floor, creating sounds like a series of large balloons popping underwater, according to Arthur Lerner-Lam, deputy director of Lamont-Doherty Earth Conservatory, which owns the research vessel
The “balloon orchestra” generates echoes off the ocean floor, Lerner-Lam said. A complex array of microphones is attached to wings that span more than three miles under the vessel. The microphones record the echoes created by the bursts of energy from the guns.
The software on board will translate the sound into a three-dimensional image.
Mountain and his team will study an area of about 370 square miles, starting in water just 15 miles off the New Jersey coast. Lerner-Lam said that the vessel will travel back and forth across the area, “like mowing a lawn with a large mower,” until the team has the data they need.
The two-dimensional images the scientists have already captured are “like a slice through cake, but you can’t understand the layers of ancient landscapes” when only a slice is provided, according to Craig Fulthorpe, another principal investigator on the project. “We want to image these the way you would look at a modern map.”
Fulthorpe, a geophysics researcher at the University of Texas, has been researching shorelines for more than 20 years. The three-dimensional images will help scientists determine if there are river valleys or tidal channels in the different layers _ features that do not show up in two-dimensional images, he said.
By using the new images and also samples of sediment collected from those layers collected back in 2009, scientists can date the layers and thus create a timeline. The deepest of the layers recorded dates back almost 40 million years.
Fossils, such as plankton _ about the size of a period on a printed page _ are particularly helpful in the dating because of their prevalence in the layers, Mountain explained.
Clean Ocean Action, a waterways protection group, fears that the increased noise in the ocean will affect behavioral patterns of endangered species. The National Marine Fisheries Service granted the group an extension to the public comment period about the plan until May 16.
While there will be marine biologists on board the Langseth to listen and watch for marine life and shut down operations if necessary, Clean Ocean Action fears they may not be able to detect the animals until it’s too late.
“Marine mammals are not always vocalizing at all times,” Cassandra Ornell, staff scientist at Clean Ocean Action, argued.
North Atlantic right whales, for instance, are an endangered species with a population of less than 500, Ornell said, and any impact on that population could have devastating consequences for the species.
The likelihood of North Atlantic right whales appearing in that area is low, according to an analysis done by LGL Limited for the Lamont-Doherty Earth Observatory and National Science Foundation. The impact on marine life, according to the report, would be “short-term, localized changes in behavior and distribution near the seismic vessel.”
Lerner-Lam said the sound generated by the air guns dissipates quickly with distance from the guns.
Other critics fear the research is a cover for oil and gas exploration. But Mountain said the area is too close to shore to be of interest to oil companies and past drilling for sediment samples has showed that the area is “dry as can be.”
Clean Ocean Action worries that the research will have negative effects on the environment, and believes that the research plans should be more thoroughly analyzed before approved. “The main concern we have is we don’t want science to have a pass,” Ornell concluded.
Despite the question, Mountain wants the research to go forward, but he needs approval from the National Marine Fisheries Service. The organization will make its final decision after the comment period ends in mid-May.
“New Jersey is the ‘sea-level state,’” Fulthorpe said, commenting on how the coast of New Jersey provides the perfect place for this type of research. “They should have it on their license plates.”
Fulthorpe explained that the research in New Jersey is important; scientists would have to also conduct the same research in other oceans to reach conclusions about global sea level changes. He has been involved in some research off the coast of New Zealand.
“We’re studying this for many scientific reasons,” he said. “But fundamentally, it helps us to understand the response of the shorelines to sea-level change.”
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