video - Mt. St. Helens Flashcards
With respect to plate tectonics, describe the cause of the Mt. St. Helens eruption.
Sits on pacific ring of fire
The plates making up the earth’s crust are being squeezed tighter
Plate below pacific is sliding under the American plate
Pressure and friction melt the rock
Magma rises and once hits surface it blows out
What did the scientists do to monitor the volcano after they realized there was potential activity in its crater? What did they learn from doing this?
Set up a time lapse camera on a nearby ridge
Pictures show a dome
Over several days, the pictures show a dome rising in the middle of the crater floor. The volcano is oozing a sticky gray lava, cooling as it reaches the surface
After several months, the domes grew larger.
How do gophers help to encourage both more plant and animal life in the pumice plain? How do elk help to encourage more animal life in the same area?
Gophers: enrich the pumice by burrowing their way through the ash. The mix in fresh soil and help new plants to spread. When walking through the land, the gopher turned soils were green and full of flower and seeds.
Create kilometers of underground tunnels
Elk: help to encourage more animal life. When elk move across the landscape, they collapse the tunnels, creating entrance ways that salamanders and other amphibians can get access to. And once they get beneath the ground, these are very cool and moist sites that enable them to survive in an otherwise inhospitable area. And the importance of that is that it allows them to use these underground burrows as stepping stones during hot, dry weather and eventually to colonize new patches of terrestrial habitat, as well as ponds and lakes.
What was causing the small signals on the seismograph that the scientists called ‘drumbeats? Why did seismic activity on the mountain stop in 2007?
Solid blocks of rock, grinding their way through the volcano, coming out onto the surface. As they do, they make small seismic signals, one just like the other, very repetitive. –> drumbeats, spine after spine
These things were like skyscrapers that were being shoved out of the ground.
Seismic activity on the mountain stopped in 2007 because the lava below the mountain had finally run out of gas.
What is the take home message from the decades of ecological work on Mt. St. Helens?
Mount St. Helens has revealed a rich and complex web of life. The slopes of the mountain are a living testimony to the miraculous ability of nature to return from the dead. Each time, they would find something new, a new species of spider. The take-home message from the decades of ecological work is that nature is very resilient.
