VOLCANOVOLCANOVOLCANOVOLCANOESESESES

1. Prepare three sentences with a gap in each one. Note that the level of the sentences has to

be adequate, since the rest of the students will have to answer the fill in the gaps you have

prepared. You also have to prepare one question about the text. Remember to bring it at class

on the 6th

of April.

A volcano erupts when Magma or an amount of lava finds a fissure or an opening in the Earth

surface and shoots out, usually along with a certain amount of gas and ash. Volcano eruptions

are shift at Earth surface by resulting in the formation of mountains and islands and other

geological formations. You are going to have volcanic activity in places where you have hotspots

for seismic activity, specifically in places where tectonic plates are being pushed together or pulled

apart. So, one specific example of that would be the Pacific Ring of Fire, which is specifically

around the Ring of the Pacific Ocean. There, you have a lot of seismic activity and, as a result, a

lot of volcanoes. The most common kind of volcanic formation is the “cinder cone”. “Cinder

cone” volcanoes often only erupt once and they form a small hill or mountain about 30 or 400

m. high. Another common kind of volcanic formation is the “stratovolcano”, it is characterized

by multiple eruptions and viscous lava that hardens before it flows very far. They usually result

in tall mountains. A “shield volcano” is a volcano formed by low viscosity lava. Low viscosity lava is

going to be able to flow a long way before hardens.

Volcanoes. [How do volcanoes work?]

http://www.youtube.com/watch?v=qrUfPJysohQ

(accessed May 18, 2010)