Presentation on theme: "Volcanic Landforms How do volcanoes change the Earth’s surface?"— Presentation transcript:
Volcanic Landforms How do volcanoes change the Earth’s surface?
Shield Volcano *Lava* Thin layers of lava cool on top of one another A wide, gently sloping mountain forms gradually over time Example: Hawaiian volcanoes
Cinder Cone Volcano *Lava* Steep, cone-shaped hill or mountain Thick lava builds up in cone producing ash, cinders, and bombs which pile up around vent after it explodes Example: Sunset Crater in Arizona
Composite Volcano *Lava* Tall, cone-shaped mountains in which layers of lava alternate with layer of ash Lava flows alternate with explosions i.e. Stratavolcano Example: Mount Fuji in Japan and Mount St. Helens in Washington state
Lava Plateau *Lava* Thin, runny lava flows out of several long cracks in an area The lava travels far before cooling and solidifying Lava flood layers upon lava flood until a raised plateau is formed over millions of years Example: Columbia Plateau in Washington, Oregon, Idaho
Caldera *Lava* Huge hole caused by the volcano collapsing after explosive eruption empties magma chamber Crater Lake in Oregon, Mount Mazama
Volcanic Neck *Magma* Magma hardens in volcano’s pipe, soft rock wears away exposing solid magma Looks like giant tooth
Dike *Magma* Magma that forces itself across rock layers and hardens Underground, horizontal channels or tubes Broadens coasts of Hawaiian islands
Batholith *Magma* Mass of rock formed when magma chamber cools inside crust Rough, jagged texture after weathering and erosion of land above batholith
Dome Mountain *Magma* Formed by small bodies of magma blocked by horizontal layers of rock which are forced upwards into dome shape
Sill *Magma* Magma squeezes between hard layers and hardens Similar to a dike, but farther up in the volcano
Can you guess the type of landform?
Indian Head Mountain, Montana
Laccolith at Fresno Canyon, north of Lajitas. Big Bend National Park, Texas. Photo credit: USGS Digital Data Series DDS-21 CD-ROM
Photograph by J.D. Griggs on 16 July 1990
Before the eruption After the eruption
photo by Tibi Marin “Magma Boulders”
John Day region in Oregon
Devil's Tower, WY Shiprock, New Mexico
United States India
Mount Aso vents a large cloud of steam at Japan's Aso National Park.
Belknap Volcano, Oregon USGS Photograph taken on October 1, 1984, by Lyn Topinka
Sill can be seen as the dark layer of rock to the left of the snow field. Glacier National Park. Photo credit: USGS Digital Data Series DDS-21 CD-ROM
Dike on south side (left) of Shiprock, a volcanic neck, in the distance. Photo credit: USGS Digital Data Series DDS-21 CD-ROM
Photograph by C. Heliker on 2 June 1986 Pu`u `O`o Eruption on Flanks of Kilauea, Hawaii
Olympus Mons: One hundred times larger than Mauna Loa
Many craters on Earth’s moon were believed to be filled by lava flows. The Moon
Volcanoes on Io This image shows what it might look like standing on the surface of Jupiter's moon, Io. A smoldering volcano can be seen against the large image of Jupiter. Smoke added with Photoshop. Background image of Jupiter is a Cassini spacecraft image taken in 2001Cassini spacecraft image while flying by Jupiter on its way to Saturn (Credit: NASA/JPL/University of Arizona).
Triton: Neptune's Largest Moon Credit: Voyager 2, NASAVoyagerNASA The above picture of Triton was taken in 1989 by the only spacecraftabove pictureTriton ever to pass Triton: Voyager 2. Voyager 2 found fascinating terrain, aTritonVoyagerfascinating terrain thin atmosphere, and even evidence for ice volcanoes on this world ofice volcanoes peculiar orbit and spin.
Geysers on Triton Credit: NASA, Voyager Project, Copyright Calvin J. Hamilton Explanation: In August of 1989 NASA's Voyager 2 spacecraft passed by Neptune,Voyager 2 the most distant of the solar system's gas giant planets. Its encounter with Neptune climaxed with its closest approach to Neptune's largest moon Triton. From a distance of about 24,000 miles the robot space probe surveyed Triton's surface, whose temperature averages nearly -400 degrees Fahrenheit (-240 degrees C), and discovered surprising evidence of a complex and active world. For example, the prominent dark streaks in this image seem to come from small volcanoes and may consist of nitrogen frost mixed with organic compounds ejected during geyser-like eruptions. Frozen, Solid Nitrogen!!!