What were the long-term responces of the eruption of mt st helens?

Answer 1

St. Helens released an amount of energy equivalent to 27,000 Hiroshima-sized nuclear weapons and ejected more than 1 cubic mile (4 km³) of material. A quarter of that volume was fresh lava in the form of ash, pumice, and volcanic bombs while the rest was fragmented, older rock. The removal of the north side of the mountain (13% of the cone's volume) reduced St. Helens' height by about 1,313 feet (400 m) and left a crater 1 to 2 miles (2 to 3 km) wide and 2,100 feet (640 m) deep with its north end open in a huge breach. More than 4 billion board feet (14.6 km³) of timber was damaged or destroyed, mainly by the lateral blast.

Downwind of the volcano, in areas of thick ash accumulation, many agricultural crops, such as wheat, apples, potatoes, and alfalfa, were destroyed. As many as 1,500 elk and 5,000 deer were killed, and an estimated 12 million Chinook and Coho salmon fingerlings died when their hatcheries were destroyed. Another estimated 40,000 young salmon were lost when they swam through turbine blades of hydroelectric generators when reservoir levels were lowered along the Lewis River to accommodate possible mudflows and flood waters.

The ash fall created some temporary but major problems with transportation, sewage disposal, and water treatment systems. Visibility was greatly decreased during the ash fall, closing many highways and roads.

Over a thousand commercial flights were cancelled following airport closures. Fine-grained, gritty ash caused substantial problems for internal-combustion engines and other mechanical and electrical equipment. The ash contaminated oil systems and clogged air filters, and scratched moving surfaces. Fine ash caused short circuits in electrical Transformers, which in turn caused power blackouts.

There were also indirect and intangible costs of the eruption. Unemployment in the immediate region of Mount St. Helens rose tenfold in the weeks immediately following the eruption By Nii Lomotey Engmann

Answer 2

Long term response:

• buildings and bridges were built
• the forest to the north was replanted
• attempts to bring back tourism
• roads were rebuilt

Natural changes were that ten years on from the eruption vegetation appeared and animals returned to the area. 1982 the area was designated a national monument and $1.4 million was spent transforming the area allowing the 3 million visitors a year to see the volcano. The Johnston Ridge observatory was built in 1997 and monitors the activity, the observatory is dedicated to the vulcanologist David Johnston who died in the 1980 explosion. A new crater grew in 2004.

Answer 3

some of the long term effects were........................................................................................................................................................................................................................

Answer 4

People could have lung problems because 250 miles of forest was destroyed

Answer 5

1. wild life
2. ash
3. crops
4. buildings
5. money
6. electrical items
7. holidays

many more...