Deep traces of the climate

2003/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Klima

To analyze the climate, scientists from twelve countries intend to deepen: In Lake Bosumtwi, in Ghana, two holes are made to extract sediments up to one kilometer deep. This aims to analyze the rotation of periods of rain and droughts that have taken place for a million years.

For scientists it is very interesting to investigate the climate of the tropics, since they want to know how it affects the Earth's climate system. It is expected that from the sediments taken from this lake numerous remains are collected. In this period of study, in addition, man evolved in Africa, so he also has a lot of interest.

When choosing Lake Bosumtwi, they have taken into account that it is located in a two-kilometer crater made by an asteroid. The Atlantic monsoons fill the lake with water and are dried by the winds of the Sahara and the Sahel. When no river reaches the lagoon and there are no cracks under it, there are no changes in sediments. Consequently, it is an ideal place for the collection of sediments. The remains of the asteroid that created the crater will also be analyzed.

Next year another group plans to carry out similar studies in the Malawi lagoon, located in the Rift valley. Comparing the results of both, they will better understand the climate of tropical Africa, with a lake to the west and another to the east.