Seawater is rising abnormally

Sea level began to rise rapidly in the late 19th century and has tripled over the past two millennia, according to a detailed analysis of swamp deposits found in North Carolina, USA.

" This clearly shows that today's skyrocketing trend is not part of a natural cycle, " said Ken Miller, who works at Rutgers University, Piscataway, New Jersey, USA. not participating in the above analysis.

Andrew Kemp, at the University of Pennsylvania, USA and colleagues spent five years analyzing swamp sediments, virtually undisturbed over the past millennium. Kemp, currently working at Yale University, USA, and his team conducted drilling in two locations, excavating the remaining microorganisms of small single-celled organisms called bark fossils with holes .

This house in North Carolina, USA, was filmed in the film Nights in Rodanthe, while researchers studied the history of rising sea levels, in the nearby area.The team found that the sea level in the region has increased faster in the past 150 years or has increased three times in the past two millennia.

Different species of pests have different salinity tolerance so the sea level changes in the millennium, thus creating a blend of species that previously lived in a certain location. , according to Benjamin Horton, co-author of the analysis, working at the University of Pennsylvania, USA. Given the current distribution of different pore species in seawater at different depths along the current coast, researchers can deduce the sea level across the two excavated sites, thanks to on the abundance of different species in the sediments. The chronology of radioactive isotopes in the bark of a peculiar insect shows sea level 2,100 years ago. The analytical results of the study were published in the Proceedings of the National Academy of Sciences, issued June 20, 2011.

" We know sea level in the past, in a broad sense, about 20,000 years ago ," Miller said. But detailed records of what happened over 2,000 years are being patched, he said.

The main data show that the sea level in North Carolina, the United States has hardly changed since 100 BC until 950 AD. Then the sea level has experienced a four-century average increase of 0.6 mm per year. Sea level did not rise again until after 1865. Since then, it has spiked an average of 2.1 mm per year. And at least for the past 80 years, Horton said, " these data fit perfectly with the tide gauge data in North Carolina in a 1-1 ratio: This is perfect ."

The results confirm the use of past general equations and changes in temperature on the sea surface to predict how sea level will rise in the future when global climate continues to warm. more, according to Aslak Grinsted, working at the Ice and Climate Center, University of Copenhagen, Denmark.

" The great thing about these new data: is really high resolution and continuous, " Grinsted said, " and quite consistent with the current global data ."