Scientists are using the world's largest "shake table" to test new construction methods for buildings in areas prone to earthquakes. They believe they have devised a system to build taller, wood-frame buildings that can still safely withstand even very powerful tremors.
Right-click (Windows) or Option-click (Mac) here to download a copy of this video in QuickTime format.
You might also be interested in:
The expression "on solid ground" is often used to describe something as stable. Usually the solid ground underfoot seems very stable. But sometimes it is not. "The ground seemed to twist under us like...more
The main force that shapes our planet's surface over long amounts of time is the movement of Earth's outer layer by the process of plate tectonics. This picture shows how the rigid outer layer of the Earth,...more
During an earthquake, energy is released in seismic waves that travel from where the earthquake starts, a place called the focus. The seismic waves radiate from the focus. Seismic waves cause intense shaking...more
Altocumulus clouds are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups and are about...more
Altostratus belong to the Middle Cloud group (2000-7000m up). An altostratus cloud usually covers the whole sky and has a gray or blue-gray appearance. The sun or moon may shine through an altostratus...more
Cirrocumulus clouds belong to the High Cloud group (5000-13000m). They are small rounded puffs that usually appear in long rows. Cirrocumulus are usually white, but sometimes appear gray. Cirrocumulus...more
Cirrostratus clouds belong to the High Cloud (5000-13000m) group. They are sheetlike thin clouds that usually cover the entire sky. The sun or moon can shine through cirrostratus clouds . Sometimes, the...more