Mount St. Helens

Mount St. Helens is an active volcano in Washington State's Cascade mountain range. Mount St. Helens erupted on May 18, 1980, causing the most deadly volcanic event in United States history.

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Mount St. Helens

When did Mount St. Helens last erupt?

Mount St. Helens is an active stratovolcano in the Cascade range in the state of Washington, approximately 53 miles (85 km) NE of Portland, OR.

On May 18, 1980, an earthquake marked the collapse of the north face of the mountain at 8:32 AM PDT. A violent pyroclastic explosion of magma occurred, hurling huge quantities of rock, ash and dust to the north and east. The eruption continued for more than nine hours before lessening around 5:30 PM PDT. 57 persons were directly killed, forests were flattened, and torrents of ash, mud, and debris choked the nearby rivers, destroying bridges and industry. Much of eastern Washington state was affected by the ash and dust plume.

(for other eruptions, see related link)

An earthquake at 8:32:17 a.m. on Sunday, May 18, 1980 caused the eruption on Mt St. Helens

Mt. St. Helens last major eruption was on may 18 1980. But this volcano remains active and often spurts ash and other debris.

The last minor eruption of Mount St. Helens was in July of 2008.
Mount St Helens last produced a few small eruptions in 2008.
The earthquake before the eruption accured at 5.00am and the eruption it's self was at 8.32.

Mount St. Helens

What type of volcano is Mount St Helens?

Mount St. Helens, an active stratovolcano, is of the composite type.

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Mount St. Helens

What is the Lead measurement ST?

Poor question; cannot be answered. The question lacks context.

Mount St. Helens
Mount Vesuvius
Mount Etna

What do Mount Etna and Mount St. Helens and Mount Vesuvius have in common?

Mount Etna, Mount St. Helens and Mount Vesuvius are all active volcanoes.

They have also all undergone plinian eruptions (named after the famous Vesuvius eruption of AD 79. The Mount St. Helens eruption was unique in that the blast projected laterally as opposed to vertically.

See related link.

Mount St. Helens

Why did Mount St. Helens erupt?

The 1980 eruption resulted when a huge section of the mountaintop was forced outward and fell away from the mountain. The pressure of magma from within the mountain had been increasing over the years and the rock eventually gave way. With the blocking rock removed, huge amounts of hot rock, ash, and gas exploded from the opening with incredible force.
As part of the Cascade Range of mountains, Mount St. Helens was formed by eruptive flows of magma as the Juan de Fuca tectonic plate is forced under the North American Plate. Beginning about 37,600 years ago, periodic eruptions and magma flows occurred in the area between Mount St. Helens and Mount Rainer.
Huge eruptions occurred in the years 1480, 1482, and 1800, and smaller releases of steam between 1831 and 1857. The large magma chamber beneath Mount St. Helens will likely continue to force lava upward and cause future eruptions. However, as history indicates, they could be several hundred years apart.
The Mount St Helens eruption was like any other volcanic eruption: namely, the build up of pressure of magma and gas in the magma chamber beneath the surface.

The eruption was caused by the Juan de Fuca plate moving east, towards the North American plate. Because the Juan de Fuca is more dense, it was forced below the lighter North American plate. These movements caused friction, which then caused a rise in temperature, which melted the earth's crust. Then, because the magma from the mantle is less dense than the recently melted North American plate, the magma rose to the surface and caused the mountain to bulge (by about 1.5 meters a day). The pressure became so great that the mountain exploded sideways.
The one that triggered the 1980 eruption of Mount St. Helens was the 5.1 earthquake that created the landslide.The dome that was bulging on the west side of the volcano also triggered the eruption.

Mt St Helens erupted due to pyroclastic flow. There was a huge blister on the north face of the mountain that grew up to 5ft a day until an earthquake took place which caused a land slide. The landslide was one of the biggest ever to be recorded and managed to pop the bulge, by Nii Lomotey Engmann.


A volcano does not erupt because it produces any given form of lava! A pyroclastic flow is one form of eruption, not its cause. The America's (N and S) volcanoes are a consequence of the Pacific Ocean closing.

Mount St. Helens

How tall is Mount St Helens now?

8,365 FT (2,550 M)

Earth Sciences
Mount St. Helens

Why did Mount Saint Helens Erupt?

The eruption was preceded by a two-month series of earthquakes and steam-venting episodes, caused by an injection of magma at shallow depth below the volcano that created a huge bulge and a fracture system on Mount St. Helens' north slope. An earthquake at 8:32:17 a.m. on May 18, 1980 caused the entire weakened north face to slide away, suddenly exposing the partly molten, gas- and steam-rich rock in the volcano to lower pressure. The rock responded by exploding a hot mix of lava and pulverized older rock toward Spirit Lake so quickly that it overtook the avalanching north face.

Mount St. Helens

When do volcanoes erupt?

Volcanoes are formed when there is a great stress inside the earth's crust and the pressure of magma reaches so high that it finds its way upward causing an eruption. Sometimes the magma chamber breaks its sides and only reaches to the flank or summit of volcano and sometimes reaches to the surface causing an eruption. In the volcanoes which are not much active supply the magma from the deeper parts of the earth is not sufficient to cause eruption so most of the times crystals forms and they go down at the bottom releasing gas in the form of bubbles which come to the top of chamber and sometimes the pressure created by these gas bubbles are enough to erupt a volcano or just wait there for a little more push which they get from the next new magma formed within the earth. The heat just triggers the magma for eruption which was there for a long time.

Magma is the melted rocks deep in the earth crust. The rocks melt because of great heat inside and forms a thick liquid called magma and when it comes to the surface it is called as lava and flows into the air in the form of ashes etc.

If the volcanic eruption is explosive then the matter forms a cloud of hot tephron. The things coming in its way are almost destroyed. Ashes which are released in the sky fell on the earth in the form of powdery snow and it doesn't melts. A huge mass of snow can cause harm to the vegetation, living organism and human beings.

The intensity of explosion depends upon the thickness of magma. The gases cannot escape easily. Hence they are accumulates inside till they get enough heat energy for the explosion.

Atom Research May Help Detect Volcanoes And Oceans

Uncovering Europa's ice to reveal the moons true surface will take extraordinary new technologies

Pasadena - Jul 24, 2002

Breakthrough research on waves of ultra-cold atoms may lead to sophisticated atom lasers that might eventually predict volcanic eruptions on Earth and map a probable subsurface ocean on Jupiter's moon Europa.

The atoms were manipulated to form tidy bundles of waves, called solitons, which retained their shape and strength. They were created in a laboratory at Rice University, Houston, under a grant from NASA's Biological and Physical Research Program through the Jet Propulsion Laboratory, Pasadena, Calif.

Normally, when a wave forms -- whether in water, light or atoms -- it tends to spread out as it travels. Not so with a soliton wave. It maintains its perfect shape without spreading. In the Rice University research, the solitons are localized bundles of atom waves.

Atom-wave solitons could be used in advanced lasers, which use atoms instead of light photons. Dr. Randall Hulet, the Rice University physics and astronomy professor who led the research team, said atom lasers may have many applications, some not yet envisioned.

"Forty years ago, no one imagined that lasers would be used to play music in our cars or scan our food at the grocery store checkout," said Hulet. "We're getting our first glimpse of a wondrous and sometimes surprising set of quantum phenomena, and there's no way to know exactly what may come out of it."

Hulet said atom lasers might improve instruments that study gravity variations to locate and measure underground water, minerals, oil, caves and volcanic magma on Earth.

"Eventually, atom-wave lasers may enhance sensors for studying Earth and various bodies in the solar system," said Dr. Lute Maleki, principal investigator for the Quantum Gravity Gradient Project at JPL. "With these advanced sensors, we'll be able to produce a 3-D map of underground features. By measuring levels of underground magma, for example, scientists may be able to predict volcanic eruptions. This technology could be used on a spacecraft to map the ocean believed to lie beneath Europa's icy crust."

In addition, atom lasers may yield extremely precise gyroscope navigation for air and space travel. Computers would run faster if atom lasers were used to write directly onto computer chips.

The first recorded observation of a soliton wave was in 1834, when a man in Scotland saw a barge stop suddenly in a canal. This created a large bow wave, which traveled at about 8 miles per hour without shrinking or spreading. The man followed the wave on horseback for about a mile until he lost sight of it in the windings of the canal.

Scientists now know that this soliton water wave formed because of particular relationships between the depth and width of the canal.

In their laboratory, Hulet and his team confined lithium atoms within magnetic fields, cooled them with lasers to one billion times colder than room temperature, and confined them in a narrow beam of light that pushed them into a single file formation. The atoms formed a type of matter called a Bose-Einstein condensate, a quantum state where classical laws of physics go out the window and new behaviors govern the atoms. Instead of hitting each other and bouncing off like bumper cars, the atoms join together and function as one entity. The team actually observed a "soliton train" of multiple waves.

Hulet co-authored a paper on the research, which appeared in the May 9 issue of the journal Nature, with Rice University graduate students Kevin Strecker and Guthrie Partridge, and Dr. Andrew Truscott, formerly a post-doctoral researcher at Rice and currently on the faculty at Australian National University in Canberra.

Mount St. Helens

Why do volcanoes erupt?

When rock inside the Earth becomes hot enough, it melts. This molten rock, or magma, is less dense than the surrounding solid rock. Just as an object that is less dense than water will float on the water, the relatively low density of the magma causes it to rise to the surface of the Earth. In the most common form of volcanism, the type caused by plate subduction, the magma rises and pools into areas beneath the surface called magma chambers. If the pressure continues to increase on the magma within the chamber, it may eventually breach the surface in an eruption. The eruption ceases when the magma chamber is fully or partially emptied, and the process of filling the chamber will begin again (so the process of eruption may occur again). Fissure eruptions occur as a result of a process of convection in the asthenosphere. Heated rock rises in the mantle, melts from decompression, and fills in the gaps created in the crustal rock at divergent plate boundaries. The mid-ocean ridge, the world's longest mountain range, is created from fissure eruptions.

'Hot spot' volcanoes (as in the Hawaiian Island Chain) erupt from a constant stream of molten material from a specific point in the Earth's mantle which remains constant as the plates move slowly across it. Eruptions here will be slow and fairly steady as the source and pressure of the magma is constant.

The magma that flows from a chamber may harden to form a "plug" or a dome. This kind of structure may enlarge or be pushed upward when the magma cannot freely flow out. The pressure on these rocks is one factor that is monitored by vulcanologists when forecasting the possibility of another eruption from an existing volcano.
Volcanoes erupt because the magma underneath them builds upward, and eventually has enough force to shoot or flow out of the volcano.

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Mount St. Helens

How many people did mt st Helens kill?

In May of 2000, a memorial plaque was placed in a grove of trees at the Hoffstadt Bluffs Visitor's Center in memory of the victims of the Mt. St. Helens eruption. Fifty-seven names are etched into the plaque.
57 people were killed directly by the eruption. There was also a plane crash, a traffic accident, and shoveling ash which killed a total of 7 more. So don't go live near mt. saint Helens. I am not saying don't go vist it I am saying don't live next to it or near it.
57 People died in the eruption.
There was a relatively low death toll due to the eruption of Mount St. Helens because most of the people were evacuated. In total, fifty-seven people died in the eruption. The people that did die were either those who refused to leave or those who were monitoring the volcano. RIP.

Mount St. Helens

Is st Helens rlfc ground seated or standing?

St Helens Rugby League Club Stadia

The current Knowsley Road Stadium, home of St Helens Rugby League Club, is a mixture of seating and standing. Seating is limited however and the ground is predominately made up of terraced stands. It is advisable to book seats as soon as possible as many sell quickly or are reserved for season ticket holders.

The Popular Side, Restaurant/Dunriding Lane End and Eddington End (where away support traditionally congregates) are all standing only. The Family Stand is all seating. Knowsley Road's capacity is 17,500.

St Helens plan to move to a new 18,000 capacity stadium which will be mostly seated. The stadium was ment to be compleated in 2010 but now will be done when the market picks up.

Mount St. Helens
Mount Vesuvius
Mount Etna

What do these 3 mountains have in common - Mount Etna Sicily... Mount St. Helens... and Mount Vesuvius?

They are all active volcanos. They all erupted in 1980's They're all part of the ring of fire

Mount St. Helens

Where is Mount St Helens located?

in Skamania Town,Washington

Mount St. Helens

Where is the best place in the western US to learn how to ski?

There are some excellent beginner slopes and instructors available in Utah. Solitude is a great secret that is shared among the locals. But don't tell anyone that I said so. ;)

Mount St. Helens

Is Mount St. Helens dormant?

No, it is not. Mount St. Helens is an active stratovolcano, and there is a bulge within its current crater area that is growing while you read this.

Mount Saint Helens is not a dormant volcano. For 123 years it was thought to be, however a bulge was noticed in the volcano, and evacuation orders took place. 57 people refused to evacuate, one of whom was 83-year-old Harry R. Truman. On Monday 8:32:17 a.m May 18, 1980, the "bulge" fell off, or slid down the mountain, exposing partly melted and gas enriched rock to lower pressure. It exploded with enough fury to send an 80,000 foot high ash column into the sky, depositing ash into 11 states.

At the same time, snow, ice, and several entire glaciers on the volcano melted, forming a series of large lahars (Volcanic mudslides) that reaches as far as the Columbia River, nearly fifty miles (eighty kilometers) to the south. 200 homes, 27 bridges, 15 miles (24 km) of railways and 185 miles (300 km) of highway were destroyed. Currently it is active.

As I learned in my natural disasters class, after a volcano has finished with it's current "explosion", it starts to rebuild itself by excluding a toothpaste consistency glob of Rhyolite. Mount Saint Helens is active in the way that it is rebuilding itself using the "glob", however it is still an Active Volcano.

If it helps any, a Dormant volcano is thought to be a "sleeping" volcano, and is simply one that currently isn't active but is capable of acting. Extinct volcanoes haven't erupted for tens of thousands of years, and aren't expected to erupt again. Mt. St. Helens is an active volcano.

Mount St. Helens

What is mount st helens most recent eruption?


Mount St. Helens

What are St Helens' eruptions like?

Mt. St. Helens has had several different styles of eruptions through its history. The types of eruptions vary from explosive to dome building.

The explosive history of Mt. St. Helens is relatively well known from the May 18, 1980 eruption that captured world attention at the time. The eruption style was typical of this volcano, pyroclastic flows and lahars were both generated. The flank collapse was more than likely a result of the earthquake under the flank at the time, and is believed to have been the trigger of the eruption itself.

Dome building eruptions have been the most common types of eruptions since the 1980 explosive eruption. There have been several lava domes generated since the summit eruption that generated the crater.

Although they have not been witnessed in historical time, Mt. St. Helens does have a history of passive lava eruptions out of flank vents. This type of eruption although it hasn't been witnessed in a rather long time, it is believed that these types of eruptions have been just as common if not more common than the explosive eruptions we have seen in historical times.

Mount St. Helens

How far away were the effects felt mount st Helens?

The eruptive effects were felt worldwide for a full year after the 1980 eruption of Mt. St. Helens. There was enough carbon dioxide as well as sulfur dioxide erupted from the volcano that it was able to measurably reduce global temperatures by 1.5 degrees. The heaviest impacted area from the eruption was the area directly to the north that was part of the blow down zone following the lateral blast from the volcano. There was also however a big impact on the central United States due to the ash fall that killed crops and injured live stock.

West Virginia
Latitude and Longitude
Mount St. Helens

Which is closer to the equator 32 degrees N latitude 18 degrees W longitude or 70 degrees S latitude 12 degrees East longitude?

The first one is much closer.

The higher the latitude number (N or S), the farther the point is from the equator. The second location 70°S 12°E is more than twice as far from the equator as 32°N 18°W.

Mount St. Helens

Where is Mount St. Helens?

Mount St. Helens is located in Skamania County, in SW Washington state, in the United States.

It is 96 miles south of Seattle Washington and 53 miles northeast of Portland Oregon in Skamania County Washington.

Plate Tectonics
Mount St. Helens

Was Mount St. Helens formed along a subduction zone or a rift zone?

Mount St. Helens was formed along a subduction zone, where the Juan de Fuca Plate plate dives under (subducts) the North American plate.

Earth Sciences
Mount St. Helens

What type of volcano is Mt St Helens?

Mount St. Helens is a composite volcano.

Mount St. Helens

Is mount st Helens active dormant or extinct?

Right now Mount St Helens is dormant.

Mount St. Helens

What type of magma does mount st. helens have?

Mt St Helen's eruption of 1980 was a pyrocastic flow diverse lava, ranging from olivine basalt to andesite and dacite). The magma is believed to come from another area laterally located to the east. Magma and rock under the volcano are cool.

Mount St. Helens

Is Marlon St Julien still riding and where?

Yes Marlon St Julien is still riding. He is currently riding in Vinton Louisiana at Delta Downs where he is 3rd in standings. 2008

Yes Marlon St. Julien is still riding. He is currently riding at Delta Downs in Vinton, Louisiana. In standings he is in 4th, and he is 52 win away from his 2000th win. Feb. 2008

rlon Yes MA


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