North-South America land connection formed from volcanic activity

Pictured: The origin of the Isthmus has been much debated. Source: Wikimedia Commons

By Milo Moran

It’s the narrow piece of land that connects North and South America, shaped the last 25 million years, and formed the Arctic ice cap, but the events which led to the creation of the Isthmus of Panama are largely disputed. However, data collected by Cardiff University scientists may sway the debate once and for all.

For a long time, it was believed that the Isthmus was created by the collision of the South American and Caribbean tectonic plates, which formed underwater volcanoes. A combination of volcanic activity, the upward pushing of the two plates, and sediment deposited by ocean currents eventually formed the land.

Geochemical data taken from the Panama Canal shows that there were high levels of volcanism in the region, suggesting that it was this which formed the new land, and not sediment. Because the Panama Canal was deliberately built in a low-lying, flat region of the country, scientists believe it was one of the last parts of the Isthmus to emerge from the ocean, and therefore holds the most recent data.

The Isthmus has caused major changes since it formed, as the division of the Pacific and Atlantic forced warm Caribbean water north, providing the moisture that formed the Arctic ice cap, and warming north-western Europe. If the Gulf Stream were to stop for any reason, Britain could become up to 10°C colder!

The Isthmus also played a huge part in the Earth’s biological history, allowing plants and animals to migrate between North and South America. Cardiff University’s Dr David Buchs, lead author of the study, quite rightly said “The formation of the Isthmus is without doubt one of the most significant geological events to have happened on Earth”, and anyone who has been feeling the cold lately will likely agree.