This is a map of the ocean floor.
Click on image for full size
Image from: NOAA/NESDIS/National Geophysical Data Center, Boulder, CO

Krakatoa

One of the most powerful volcanic explosions in the history of the world occured at Krakatoa in the last century. Krakatoa was formerly a volcanic island between Java and Sumatra.

In August 27, 1883, a gigantic explosion blew the island apart.

The large explosion was due to super-hot steam, which was created when the walls of the volcano broke and let sea water into the magma chamber.

The island exploded with the force of a 100 megaton bomb. The explosion was heard as far away as Madagascar (2,200 miles). Ash from the explosion rose so high that it affected weather patterns for the next year. Tidal waves from the explosion destroyed 163 villages along the coast of Java and Sumatra.


You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Volcano Formation

Volcanoes form when hot material from below risesand leaks into the crust. The hot material, called magma, rising from lower ground, gathers in a reservoir called the magma chamber. Eventually, but not...more

Volcanic Ash

Ash is formed as a volcano erupts when rocks made by the volcano blow apart into millions of tiny pieces. The rocks are still very hot, because they just formed from lava. If the hot rocks come into contact...more

Content for Climate Change Education Courses

Looking for online content that can be used for a climate change education course or module? Pages linked below can be used to support an introductory climate change education for either a unit or a full...more

Cinder Cones

Cinder cones are simple volcanoes which have a cone shape and are not very big. Compare the size of this volcano to the strato-volcano in this image. They are usually made of piles of lava, not ash. During...more

Flowing Lava

Lava can move in two ways, wide flat lava flows, or through channels which squeeze the lava into a small area. The fastest lava flows move at about 6 mi/hr, an easy jog, but they average between 2/3 and...more

How Do Plates Move?

Plates at our planet’s surface move because heat in the Earth’s core causes molten rock in the mantle layer to flow. We used to think the Earth’s plates just surfed on top of the moving mantle, but now...more

Clues to Plate Movements

Many kinds of surface features are clues to a sliding lithosphere. Two types of features can form when plates move apart. At ocean ridges, the crust splits apart to make room for molten mantle rock. Continental...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA