International News Archive - April 21, 2012
Researchers say they have created the most detailed map yet of groundwater across the entire continent of Africa.
The Popocatepetl volcano located outside of Mexico City has started spewing ash and fragments of glowing, molten rock thousands of feet down its slopes, forcing officials at one of the world's largest cities to increase the volcano's alert level.
- The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter.