Ice age XXV

Ice ages and Iceland's age.

Iceland is only 18 million years old. Which is very young compared to hundreds of million year old continents on both sides of the Atlantic ocean. The first 15 million years Iceland was a warm place hosting plenty of lifeforms including about 140 types of trees. Trees like palm trees and the sort you would normally find in a tropical forest. But things change.

The last three million years there have been between 20 and 25 Ice ages on our little blue planet. When an Ice age occurs the ice on the polar areas grows dramatically towards the equator. Last Ice cap covered much of North America, northern Europe and Asia. In many areas the Ice gets thousand of meters in thickness. In Iceland the Ice became up to 1500 meters thick (4500 ft) and while it was building up it pressed the land down and the ice to the sides. The ice finds the easiest way and goes into cracks and river beds scraping the surface on its way. This scraping goes on until the ice starts to retreat again in the next warm period leaving behind some big moraines, valleys from the mountains to the ocean and bays on the ocean floor. 

Ice ages last typically over 100 thousand years and the warm periods between them are usually much shorter. After each ice age the land is completely bare. No vegetation, no animals, not even insects so everything has to start from 'literally' scratch. Last ice age finished 12-14 thousand years ago after almost 100 thousand year long Ice age. Iceland was ice free and without glaciers 3-4 thousand years ago. The glaciers in Iceland started to form again about 2500 years ago and have been growing more or less since then or up until last century when they started retreating again. The picture is from Skaftafell glacier tongue sliding down from Vatnajökull which in fact is Europa's biggest glacier of 8,1 thousand square kilometers or 3,1 thousand cubic meters.

After the first ice age in Iceland the vegetation started again and right before the next one there were about 110 types of trees. We can see this by looking at microscopic fossilized pollen. After the next and before the third ice age there were even fever types of trees. This has repeated through out all the warm periods between the ice ages and after the last one XXV that finished 12-14 thousand years ago, when the vikings arrived in Iceland 1100 years ago, there were only 4 types of trees. This is shocking! What has changed? Well botanists say this can only mean one thing. The warm periods on our planet is getting colder and colder by every ice age. When will we see Ice age XXVI?