By: J. van der Gaag
When scientists study volcanic eruptions, one of the challenges they face is how to compare different events, past and present, in a meaningful way. One of the tools developed to address this challenge is the Volcanic Explosivity Index (VEI), created in 1982 by Chris Hewhall...
A guide to using the Volcanic Explosivity Index (VEI)
By: Marisol Dayton
Not all volcanoes are created equal. Nor do they erupt equally. As hurricanes have the Saffir-Sampson scale, tornadoes have the Fujita scale, and earthquakes have the Richter scale, volcanoes have the Volcanic Explosivity Index. The VEI was first proposed in 1982 by Christopher Newhall and...
By: Michael Fassbender
People are often at a loss to describe the power of a volcanic eruption. When earthquakes are discussed, the classification of the Richter Scale comes readily to the public at large. News reports can even offer this information in shorthand, saying that a given tremor...
By: Michael Fassbender
It is the classic image of a volcano: a tall mountain that looms over the surrounding countryside, growing progressively steeper as one approaches the summit. There, a large crater marks the spot from which past eruptions have issued. In erupting, the stratovolcano suits the popular...
By: Kayla Willis
Magma and lava are terms which are usually used interchangeably. The one major difference which separates one from the other has to do with location, location, location. Simply put magma is molten rock underneath the ground whereas lava is molten rock which has flowed out...
How rock collectors can identify specimens of rocks and minerals
By: Frances Stanford
In order to classify rock specimens scientists must conduct a series of tests in order to identify them. This testing is essential because so many rocks and minerals look so much like one another. This article will provide a brief explanation of the following scientific...
By: Hai Shunxi
The Mohs Scale of Mineral Hardness was developed in 1812 by a German mineralogist, Frederich Mohs (his name rhymes with “toes”). His simple, ten-step scale has become a basic testing tool widely used by geologists and geology students for identifying mineral samples. The...
By: Elizabeth M Young
During the 1980s Lake Monoun and Lake Nyos in Cameroon exploded. Lake Monoun exploded on August 15, 1984 with witnesses describing a loud noise, and a gas cloud that emanated from part of the lake. 37 people were killed, with some confusion as to the...
The meaning of desert encroachment
By: Hai Shunxi
To encroach upon something means to advance past its usual or natural limits, so when we pair the words “encroachment” and “desert,” we refer to the spread of a desert into surrounding lands.Though “desert” usually conjures up an image of...
By: Tim Harry
The cold weather in Britain will see the gritters out on the road, but rather than making use of the traditional grit, gritters now spread rock salt. Rock salt itself is now mined in huge amounts, and such mines are located all around the world...

 

1 39 40 41 42 43 93