The Earth’s Crust on the Move


The exhibition zone 1 of the Sirindhorn Museum is put together under the concept of "Universe and the Earth”. In addition to the presentation on the birth of the universe, we will also learn about how our planet came into being.

The large globe mounted on the wall displays the earth structure with several layers of earth crusts. Visitors can move those metal earth crusts back and forth in order to understand how our earth was formed in layers and has been in a constant movement.

The top layer of the earth, known as earth crust, consists of hard rock. The continental crust averages 35 km thick, while the oceanic crust is average only 6 km thick.

Under the crust is the Upper Mantle. Two main zones are distinguished in the Upper Mantle. The Inner asthenosphere composed of highly viscous flowing rock about 300 km thick and roughly 1,400-3,000ºC. The Lower lithosphere composed of rigid rock about 2,600 km thick and roughly 3,000ºC under high pressure.

Next is the Outer Core, which is about 2,300 km thick, composed of liquid iron and nickel alloys with temperature between 4,000-5,000 ºC.

The deepest core is the Inner Core. The round shaped inner core is roughly 2,400 km diameter and approximately 5,000-6,000 ºC. As the pressure exponentially increases, the nickel-iron alloys in the inner core becomes solid due to the extreme pressures.

Now you can see that the earth crust is mostly composed of several thin layers of rocks that are floating on the highly viscous rock. The tectonic plates then migrate across the surface under the centrifugal force on earth surface.

The movement of tectonic plates has an enormous impact on the global environment and development of lives on earth including the dinosaurs.