Marine geologist available to talk about research into rising sea levels

April 1, 2010

GAINESVILLE, Fla. — University of Florida marine geologist John Jaeger joined a team of more than 30 scientists on a nine-week drilling excursion off the coast of New Zealand to explore the global concern for rising sea levels.

Scientists from around the world gathered to participate in the Integrated Ocean Drilling Program’s Canterbury Basin Sea Level Expedition 317. The goal of the expedition that ended in January was to observe how sea level has changed during the past 30 million years. The Canterbury Basin was chosen for its strong oceanic water signals and high-resolution temporal record of sea level change.

Over the last 40 years, sea level has risen at rates 50 percent faster than current climate change models predicted, and by 2100 sea levels may be over 20 inches higher than they are now, Jaeger said.

Rising sea level impacts more than just the shoreline position. Higher sea levels lead to more frequent coastal flooding and greater invasion of seawater into freshwater coastal aquifers, a huge impact for a state like Florida where large population centers such as Miami are found right on the coast and get most of their drinking water from such aquifers, he said.

According to Jaeger, more than 600 million people worldwide live in low elevation coastal zones, areas that are less than 30 feet above sea level. Many of the large cities and barrier islands in Florida fall within this zone, putting these areas in danger for flooding.

Jaeger said the ability to better understand the causes and magnitudes of sea level changes is one of the key components of climate change research.

“It was a once-in-a-lifetime opportunity for any marine geologist who studies the long-term impacts of changing sea level,” said Jaeger.

The expedition included several record accomplishments for scientific ocean drilling. He said drilling with a dynamically positioned drillship has historically been a challenge in the relatively shallow waters of continental shelves, the seaward continuation of coastlines. The expedition reached record drilling depths of more than half of a mile, or 3,400 feet, on the continental shelf and more than 1.2 miles on the nearby continental slope, becoming the deepest hole drilled on a single expedition in the history of scientific ocean drilling. It was also the deepest sample taken by scientific ocean drilling for microbiological studies at 6,300 feet.

“Together, these record-setting accomplishments will allow for an unprecedented scientific view of million-year long changes in global sea-level, the paleoclimate history of an understudied part of the Earth and of the environmental limits of life on this planet,” he said.

The Canterbury expedition was one of four expeditions. Other expeditions occurred near New Jersey, the Bahamas, Tahiti and Australia.

Jaeger can be reached at 352-846-1381 or jmjaeger@ufl.edu.