Prof. Dr. Ulrich Hansen
Corrensstraße 24 48149 Münster
Tel.: +49 251 83-33590
Fax: +49 251 83-36100


The Earth's flow

Appearance and magnetic field of the earth are influenced by convection


Ulrich Hansen & Jörg Schmalzl

The structure of the earth
Dynamic Earth
The instruments of geodynamics: Scientific computing and modeling
Mantle convection as impulse of plate tectonics
The origin of the Earth's magnetic field


Earthquakes and volcanic eruptions demonstrate again and again that we are living on a turbulent planet. For a moment such natural phenomena let us imagine, which immense forces affect inside the earth. The same forces, which destroy peoples work in seconds have shaped the surface of the earth for a long period, have formed mountains and ocean basins and created the framework for the development of life. The atmosphere which is so important for us is not at least the product of exchange processes between the earth, the oceans and the atmosphere. For people not directly noticeable is another important feature of our planet. The earth has a magnetic field. We don't know anything precise about the importance of the earth's magnetic field for life on earth.The magnetic field protects the earth from the solar wind, a stream of electrically charged particles which constantly come from the sun. Also cosmic radiation, radioactive radiation from space is protected to a large part by the earth's magnetic field. Today it seems to be evident that the mechanism which created and still maintains the earth's magnetic field can be found in the deep earth.

The research of these processes is the subject of Geodynamics. During the last twenty years Geodynamics has developed within Geophysics. Until then Geophysics has delivered the most important informations about the structure of our planet. Now the dynamic processes which are responsible for the constant change in shape of the earth will be investigated by Geodynamics. In 1924 the German meteorologist Alfred Wegener pointed out a picture of the dynamic earth. He mapped out the hypothesis of continental drift what means continents which move in relation to each other. However,  his idea was met with non-open ears especially because nobody could imagine which driving mechanism stuck behind the movement of such immense masses. Today we know that Wegener's idea of continental drift wasn't completely correct, but included many apects of todays idea of plate tectonics.

In this article I will take up two recent fields of research, both handled at the Institute for Geophysics, WWU Münster. It is about mantle convection, a flow inside the earth which ultimatley is the impulse mechanism of all tectonic phenomena and about the phenomenon of the Geodynamo, on which the process of the Earth's magnetic field is based.

Before I turn to theses themes I will briefly present the current knowledge about the structure of our planet.

Imprint | © 2008
Prof. Dr. Ulrich Hansen
Corrensstraße 24
· 48149 Münster
Tel.: +49 251 83-33590 · Fax: +49 251 83-36100