We were not sure when the first small tremors word to define , or vibrations definition , began, but for days we knew that something big was about to happen.
We were fearful of a big, destructive earthquake word to define — a sudden, powerful shaking one long definition of the ground caused by movements one long definition of the earth's crust one long definition .
Many of the nearby landforms word to define , or natural features of the Earth's surface definition , showed that there had been much activity here.
We also knew that our state is located in the area of great volcanic activity definition encircling the Pacific Ocean definition called the Ring of Fire word to define .
Under the Pacific Ocean is the largest of the gigantic slabs of solid rock definition (tectonic plates word to define ) that make up the Earth's crust.
Huge forces are at work wherever the Pacific plate collides word to define , or runs into definition , other plates.
The area where two tectonic plates come together definition , called the plate boundary word to define , is where earthquakes happen.
This is also the home of many volcanoes word to define , or cone-shaped mountains long definition that release lava, ash, and gas long definition through openings at their tops or along their sides. long definition
As you may already know, lava is molten word to define , or liquid definition , rock.
A volcano erupts word to define when it releases lava, ash, and gas. definition
There are many volcanoes in the Ring of Fire that are extinct word to define , that is, they have not erupted during historical times definition .
Many other volcanoes are dormant, word to define since they have been inactive for a long time long definition but are capable of erupting again long definition .
Some of the volcanoes in the Ring of Fire are active word to define , that is, currently erupting long definition or having recently erupted long definition .
There are two ways a volcano can release liquid rock definition , or lava word to define .
One way is for the lava to erupt from the crater word to define , the large, bowl-shaped hole long definition forming a volcano's mouth long definition .
Another way is for the lava to erupt through a crack on the side of a volcano definition called a fissure word to define .