Volcano Knowledge Quiz

Shield volcanoes are broad and gently sloping volcanoes with low viscosity lava (basaltic) and typically non-explosive eruptions.

Shield volcanoes do not form soaring mountains with conical peaks like composite volcanoes. They are broad with gentle slopes and have a convex shape.

Mauna Loa and Mauna Kea in Hawaii are examples of shield volcanoes.

<p>Shield volcanoes are usually constructed almost entirely of basaltic and/or andesitic lava flows which were very fluid when erupted.</p> Signup and view all the answers

<p>They are built by repeated eruptions that occurred intermittently over vast periods of time (up to a million years or longer).</p> Signup and view all the answers

<p>Active volcanoes have a recent history of eruptions; dormant volcanoes have not erupted for a very long time but may erupt at a future time; extinct volcanoes are not expected to erupt in the future.</p> Signup and view all the answers

<p>Rhyolitic lava has high viscosity, rich in silica, and leads to more explosive eruptions. An example of a location where it has been observed to erupt is the Yellowstone Caldera in the USA.</p> Signup and view all the answers

<p>Pahoehoe lava is a type of basaltic lava with a smooth, undulating, or ropy surface. It forms when the lava is still partially molten and can flow for long distances. An example of a location where pahoehoe textures are often exhibited is the lava flows from Kilauea in Hawaii.</p> Signup and view all the answers

<p>Aa lava is a more viscous basaltic lava with a rough, blocky surface, formed when the lava has a higher gas content and breaks into angular, sharp-edged fragments. An example of a location where aa lava has been produced is during eruptions in Hawaii, such as those from Mauna Loa.</p> Signup and view all the answers

<p>Blocky lava refers to lava that solidifies into large, angular blocks and is often associated with andesitic and dacitic lavas. An example of a volcanic event that produced blocky lava is the 1980 eruption of Mount St. Helens.</p> Signup and view all the answers

<p>Obsidian is a type of volcanic glass formed when felsic lava cools quickly. It lacks a crystalline structure and has a smooth, glassy appearance. Examples of volcanic regions where obsidian can be found include the Glass Buttes in Oregon (USA) and Lipari in Italy.</p> Signup and view all the answers

<p>Composite volcanoes are steep-sided, symmetrical cones built by both lava flows and layers of ash and other volcanic debris. They often have explosive eruptions due to intermediate to high viscosity magma. An example of a composite volcano is Mount St. Helens (USA).</p> Signup and view all the answers

<p>Cinder cone volcanoes are steep-sided, conical hills formed by the accumulation of volcanic debris ejected during explosive eruptions. They are typically composed of basaltic lava fragments. An example of a cinder cone volcano is Paricutin (Mexico).</p> Signup and view all the answers

<p>Lava domes result from the slow extrusion of highly viscous lava, forming steep-sided mounds and leading to explosive eruptions. An example of a lava dome is Novarupta Dome (Alaska).</p> Signup and view all the answers

<p>Calderas are large, basin-shaped volcanic depressions formed by the collapse of a volcano after a massive eruption or the emptying of a magma chamber. An example of a caldera is Yellowstone Caldera (USA).</p> Signup and view all the answers

<p>Submarine volcanoes are located underwater and can form seamounts or even emerge as islands if they reach the ocean's surface. An example of a submarine volcano is Axial Seamount (underwater off the coast of Oregon).</p> Signup and view all the answers

<p>Fissure vents are long cracks in the Earth's surface from which lava erupts, often resulting in extensive lava plateaus. An example of a fissure vent eruption is The Laki fissure in Iceland.</p> Signup and view all the answers

<p>Stratovolcanoes are steep-sided cones formed by lava flows and layers of ash and volcanic debris, often with explosive eruptions due to intermediate to high viscosity magma. They are composed of lava flows, pyroclastic deposits, and mudflow deposits, and are known for their picturesque appearance with snow-covered peaks. Examples include Mount St. Helens (USA) and Mount Fuji (Japan).</p> Signup and view all the answers

<p>Cinder cone volcanoes are steep-sided, conical hills formed by volcanic debris ejected during explosive eruptions, typically composed of basaltic lava fragments. They are often surrounded by dark lava flows. Examples include Paricutin (Mexico) and Sunset Crater (USA).</p> Signup and view all the answers

<p>Lava domes result from the slow extrusion of highly viscous lava, forming steep-sided mounds and leading to explosive eruptions. They can occur as volcanic edifices in their own right or within calderas. Examples include Novarupta Dome (Alaska) and Mount St. Helens lava dome (USA).</p> Signup and view all the answers

<p>Calderas are large, basin-shaped volcanic depressions formed by the collapse of a volcano after a massive eruption or the emptying of a magma chamber. Examples include Yellowstone Caldera (USA) and Crater Lake (USA).</p> Signup and view all the answers

<p>Submarine volcanoes are located underwater and can form seamounts or even emerge as islands. Examples include Axial Seamount and Loihi.</p> Signup and view all the answers

<p>Fissure vents are long cracks in the Earth's surface from which lava erupts, often resulting in extensive lava plateaus. They have the potential for large volume volcanic eruptions.</p> Signup and view all the answers