Volcanoes By: Graham Nyhan and Cameron Lyons

Part 1 The science behind a volcano What conditions can cause a volcano? When, how and why a volcano occurs. Definition of a volcano. Where does a volcano occur? A picture of a volcano. Is a volcano related to another type of disaster? Which one and why and how? Vocabulary of volcanic terms.

What conditions can cause a volcano? A volcano begins as magma which rises from deep inside the earth toward the surface. As the gas-filled magma rises, it melts gaps in the surrounding rock and forms a large chamber. Pressure from the solid rock around it forces the magma up to the surface through the channel in a weakened part of the rock. The gas and melted rock blast out an opening called the central vent.

When, how and why does a volcano occur? A volcano occurs when molten rock becomes strong and pressure from gases push the magma to the surface of the volcano. It then busts out of a chamber called the central vent. Then the magma changes to lava as it spills out of the volcano. A volcano occurs because of the plates shifting and the pressure in the magma making it rise to the surface of a volcano.

Definition of a volcano The definition of a volcano is a large earth opening that spills out lava, rocks and gasses.

Where does a volcano occur? They can occur all over the earth and even underwater.

Is a volcano related to another type of disaster? Which one, why and how A volcano is related to a couple types of disasters and they are the earthquake and Tsunamis. They are related because sometimes when a volcano erupts, it can cause an earthquake because of the force of the eruption of the volcano. It is related to a tsunami because an underwater volcano can displace the land under the water causing a Tsunami.

Vocabulary Magma- Molten mixture of rock- forming substances, gasses and water vapor. Lava- When magma reaches the surface. Lahars- A mudflow containing volcanic ash and rock. Ring of fire- Major volcanic belt. Island arc- Resulting volcanoes create a string of islands. Hot spot- Area where magma from the mantel melts through the crust like a blow torch. Magma chamber- A pocket of magma. Pipe- Long tube in the ground that connects the magma chamber to earths surface. Vent- Opening where molten rock and gas leave the volcano. Lava flow- Area covered by lava as it pours out of a vent. Crater- Bowl-shaped area that may form at the top of a volcano around the volcanoes central vent. Silica- A material that is formed the elements, oxygen and silicon. Pahoehoe- Fast moving hot lava. Aa- lava that is cooler and slower moving. Pyroclastic flow- occurs when an explosive eruption hurls out ash, cinders and bombs as well as gases. Active- A live volcano. Dormant- Sleeping or non-active volcano.

Vocabulary (cont.) Extinct- Dead volcano. Hot spring- Forms when ground water, heated by a nearby body of magma, rises to the surface and collects into a natural pool. Geyser- A fountain of water and steam that erupts from the ground. Geothermal energy- A clean reliable source in volcanic areas, where water is heated by magma. Shield volcano- Lava flows gradually build a wide, gently sloping mountain. Cinder cone- A steep- cone shaped hill or mountain. Composite volcanoes- Tall, cone- shaped mountains in which layers of lava alternate with layers of ash. Lava plateaus- High, level areas formed by eruptions of lava. Caldera- The huge hole left by the collapse of a volcanic mountain. Volcanic neck- Forms when magma hardens inside a volcanoes pipe. Dike- Magma that forces itself across rock layers. Sill- When magma squeezes between layers of rock. Batholiths- A mass of rock formed when a large body of magma cools inside the crust. Dome mountains- Forms when rising magma is blocked by horizontal layers of rock.

Part 2 History of Mount. St. Helens eruption in 1980.

Mt. St. Helens eruption Mount. St. Helens erupted on May 18, On May 18th, 1980 the eruption of Mount St. Helens in southwest Washington state disrupted the lives of thousands and changed more than 200 square miles of forest into a grey, landscape. Now, more than twenty- six years later, the land around the mountain is slowly getting more life to it. Nature may be covering the evidence of the 1980 eruption, but many people will never forget what happened that day.

Mount. St. Helens interesting fact. One interesting fact about Mount. St. Helens is that it took 2 months for the volcanic ash to travel 1,000 miles where it was eventually all dropped to the surface in North Dakota.

Pictures of the event before, during and after

Inserted PowerPoint The following slides contain a PowerPoint of Mount. St. Helens From google.com.

October 24, 1980 a new dome started growing. This October dome was 112ft high and 985 feet wide making it taller than a nine-story building and wider than the length of three football fields

USGS Scientist Explore Pumice Blocks from a Pyroclastc flow October 17, 1980

Geologists install a seismic station near the dome. An increase in seismicity is often the first precursor to an approaching eruption

Measuring magnetic field in crater 6/18/84 Geologist measured the strength of the magnetic field surrounding the dome. The strength of the field increased as the dome cooled and magnetic minerals formed. During the eruptions, the strength usually changed rapidly as magma heated and deformed the dome

USGS scientists survey the dome 5/26-84

April 18, 1988 USGS Deformation Monitoring on the Dome

Mt. St. Helens, Sept. 1994

Aerial View of Mt. St. Helens 2002

Mt.St Helens night shot of Dome

Mt.St Helens Spirit Lake before The May1980 Eruption

USGS Scientist Explore Pumice Blocks from a Pyroclastc flow October 17, 1980

Geologists install a seismic station near the dome. An increase in seismicity is often the first precursor to an approaching eruption

5/19/82- Plume from Harry's Ridge Plumes of steam, gas, and ash often occurred at Mt. St. Helens in the early 1980’s. On clear days, they could be seen from Portland Oregon, 50 miles to the south

Harry's Ridge Was Named After Harry Truman of Spirit Lake

Measuring magnetic field in crater 6/18/84 Geologist measured the strength of the magnetic field surrounding the dome. The strength of the field increased as the dome cooled and magnetic minerals formed. During the eruptions, the strength usually changed rapidly as magma heated and deformed the dome

USGS scientists survey the dome 5/26-84

April 18, 1988 USGS Deformation Monitoring on the Dome

Mt. St. Helens, Sept. 1994

Aerial View of Mt. St. Helens 2002

Mt.St Helens night shot of Dome

Mt.St Helens Spirit Lake before The May1980 Eruption

Mt.St. Helens Lake Reflection- After the Eruption Picture taken May 19, 1982

Part 3 Safety precautions we should take in the situation of a volcano occurring. What you should do if you are present during a volcano. What you should do after a volcano.

Safety precautions we should take if a volcano occurs If a volcano occurs you should evacuate the area and leave the presence of that eruption. If you can’t leave then close all of the windows and doors and stay inside. Wear long-sleeve shirts and pants and other protective wear to protect yourself from the harmful gases and rock.

What you should do after a Volcano occurs Clear roofs of debris and ash fall. Stay out of the damaged areas and use simple precautions until you receive help.

Bibliography Google.com Youtube.com Ask.com