THE fiercest volcanic eruptions affect global sea level much more than we thought.
Particles from a big eruption block sunlight, cooling the oceans. Modellers thought this might cause a drop in sea level, as cooler water is more dense. In fact, sea levels shoot up after an eruption 鈥� at least at first, say Aslak Grinsted of the University of Lapland in Finland and colleagues.
The researchers used tide-gauge records to determine sea level after five major eruptions since 1890, removing other effects. They found levels rose by around 9 millimetres after each eruption. Grinsted thinks this is because cooling reduces evaporation, while rivers continue to top up oceans.
Advertisement
A year later, though, levels fell from that peak by 16 millimetres. One reason could be that more water remained in glaciers, says Grinsted (, ).
Mysteries of the Deep Sea -The deep sea is one of the harshest habitats on Earth, but is home to many remarkable creatures. Learn more in our comprehensive special report.
