Download Jennifer Davis volcano research

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
Jennifer Davis volcano research
04-05-11
Devils Post Piles:
What? Where? How?
Devils Postpile National Monument is located near Mammoth Mountain in extreme
northeastern Madera County in eastern California. It was established in 1911, and protects
Devils Postpile, an unusual formation of columnar basalt.
Devils Tower: What? Where? How?
Devils Tower (Lakota: Mato Tipila, which means “Bear Lodge”) is a monolithic igneous intrusion or
volcanic neck located in the Black Hills near Hulett and Sundance in Crook County, northeastern
Wyoming, above the Belle Fourche River. It rises dramatically 1,267 feet (386 m) above the
surrounding terrain and the summit is 5,112 feet (1,558 m) above sea level
Jennifer Davis volcano research
04-05-11
Caldera: What? How formed?
When a very large volume of magma is erupted, the overlying rocks may collapse. The collapse
produces a hole or depression at the surface called a caldera.
Lava Plateau: What? How Formed?
Jennifer Davis volcano research
04-05-11
Lava plateaus are formed by the large outpourings of fluid lava from long narrow openings in
the crust. During each eruption, the lava flows out from these openings, solidifies and builds up
layer upon layer each time.
A pretty good example will be the Columbia Plateau in the USA.
Hot Spot: Inter-plate Volcanic Activity?
What?
How?
Where?
Although most volcanic rocks are generated at plate boundaries, there are a few exceptionally active sites
of volcanism within the plate interiors. These intraplate regions of voluminous volcanism are called
hotspots. Twenty-four selected hotspots are shown on the adjacent map. Most hotspots are thought to
be underlain by a large plume of anomalously hot mantle. These mantle plumes appear to be generated
in the lower mantle and rise slowly through the mantle by convection. Experimental data suggests that
they rise as a plastically
Jennifer Davis volcano research
04-05-11
they rise as a plastically deforming mass that has a
bulbous plume head fed by a long, narrow plume tail. As the head impinges on the base of the
lithosphere, it spreads outward into a mushroom shape. Such plume heads are thought to have diameters
between ~500 to ~1000 km
Most Dangerous Volcano? Where
A recent PBS documentary identified Kilauea, on the island of Hawaii, as “The Most Dangerous
Volcano in the World.” A curious choice, in my opinion, for any rating of a volcano's danger
must take into account both the intrinsic hazard and the number of lives at risk.
Most Active? Where?
Many volcanoes have been in continuous eruption for decades. Etna, Stromboli, and Yasur have been
erupting for hundreds or thousands of years.
The following 4 volcanoes emit the most lava. Kilauea (Hawaii), Mt Etna (Italy), Piton de la Fournaise
(Réunion), Nyamuragira, (D.R. Congo)
Largest Volcano on Earth? Where?
Rising gradually to more than 4 km above sea level, Mauna Loa is the largest volcano on our
planet. Its long submarine flanks descend to the sea floor an additional 5 km, and the sea floor in
turn is depressed by Mauna Loa's great mass another 8 km. This makes the volcano's summit
about 17 km (56,000 ft) above its base! The enormous volcano covers half of the Island of
Hawai`i and by itself amounts to about 85 percent of all the other Hawaiian Islands combined.
Largest Volcano in our Solar System? What kind?
Jennifer Davis volcano research
04-05-11
The largest volcano in the Solar System also happens to be the largest mountain in the Solar
System; isn’t that convenient. Don’t look on Earth. To find the biggest volcano, you’ll need to
travel to Mars to see the mighty Olympus Mons.
The Volcano is named after?
(Roman God)
ur mum
3 kinds of Pyroclastic materials? Size?
1. Shield
basaltic composition
runny, low viscosity lava
sides slope at 15 degrees or less
(resembles a Roman shield lying on the ground, hence its
name) characterized by relatively quiet eruptions with lava
flows
relatively little explosive activity
Mauna Loa Volcano, Hawaii, a shield volcano, as viewed from the summit of
Kilauea, about 33 miles to the southeast.
Mauna Loa, on the Big Island of Hawaii, is the largest
active volcano in the world. It last erupted in 1984. Mauna
Loa erupted 14 times in the 20th Century, and 37 times
since 1832. Mauna Loa is the most massive mountain on
Earth, rising to an elevation of 13,677 feet above sea level,
Jennifer Davis volcano research
04-05-11
or 31,677 feet above the sea floor. Its volume is 10,000
miles3.
The tallest mountain on Earth is located nearby, also on
the Big Island of Hawaii. It is Mauna Kea, rising to an
elevation of 13,796 feet above sea level, or 31,796 feet
above the sea floor.
Both Mauna Loa and Mauna Kea are shield volcanoes.
In comparison, Mt. Everest (in the Himalayas), the highest
point on Earth above sea level, rises to an elevation of
8848 m (or 29,028 ft). Mt. Everest is NOT a volcano,
however.
The largest volcano in the Solar System is located on the
planet Mars. Its name is Olympus Mons (or Mount
Olympus), and it is three times as high as the largest
volcanoes on Earth (nearly 27 km high). It is about 100
times as massive as one of the Hawaiian volcanoes.
2. Cinder Cone
relatively small (less than 300 m or 1000 ft high)
relatively steep slopes (30 - 40 degrees)
made of pyroclastic material
Jennifer Davis volcano research
04-05-11
Cinder cone, Puu Puai, created by eruption in 1959, Devastation Trail,
Kilauea, Hawaii Volcanoes National Park.
The volcano Paracutin, in Mexico, is a well-known example
of a cinder cone.
3. Composite Volcano or Strato-volcano