Volcano Lecture ppt
... Volcanic eruptions Viscosity of magma – factors • Temperature (hotter magmas are less viscous) • Composition [Si02 (silica) content] • High silica – high viscosity (e.g., rhyolitic lava) • Low silica – more fluid (e.g., basaltic lava) • Dissolved gases (volatiles) • Mainly water vapor and carbon ...
... Volcanic eruptions Viscosity of magma – factors • Temperature (hotter magmas are less viscous) • Composition [Si02 (silica) content] • High silica – high viscosity (e.g., rhyolitic lava) • Low silica – more fluid (e.g., basaltic lava) • Dissolved gases (volatiles) • Mainly water vapor and carbon ...
Cornell Notes Template
... Viscous lava has lots of silica and is thick. It traps large amounts of gases and causes violent, explosive eruptions o Example- Mount St. Helens Violent eruptions usually eject pyroclastic material (rock fragments) from the vent. The pyroclastic material can range in size from ash to volcanic block ...
... Viscous lava has lots of silica and is thick. It traps large amounts of gases and causes violent, explosive eruptions o Example- Mount St. Helens Violent eruptions usually eject pyroclastic material (rock fragments) from the vent. The pyroclastic material can range in size from ash to volcanic block ...
What is like living near a volcano?
... • In Uganda, a country trying hard to increase its tourist industry, the volcanic region around Mt Elgon is being heavily promoted for it's landscape, huge waterfalls, wildlife, climbing and hiking and its ...
... • In Uganda, a country trying hard to increase its tourist industry, the volcanic region around Mt Elgon is being heavily promoted for it's landscape, huge waterfalls, wildlife, climbing and hiking and its ...
why live enar a volcano
... • In Uganda, a country trying hard to increase its tourist industry, the volcanic region around Mt Elgon is being heavily promoted for it's landscape, huge waterfalls, wildlife, climbing and hiking and its ...
... • In Uganda, a country trying hard to increase its tourist industry, the volcanic region around Mt Elgon is being heavily promoted for it's landscape, huge waterfalls, wildlife, climbing and hiking and its ...
Monitoring Methods
... Chemistry — As the molten material (magma) rises to shallow levels, gases are released and they rise to the surface. Gas — When molten material (magma) moves into a volcano it gives off volcanic gas emissions, sulphur dioxide (SO2), carbon dioxide (CO2) and hydrogen sulphide (H2S) which are measured ...
... Chemistry — As the molten material (magma) rises to shallow levels, gases are released and they rise to the surface. Gas — When molten material (magma) moves into a volcano it gives off volcanic gas emissions, sulphur dioxide (SO2), carbon dioxide (CO2) and hydrogen sulphide (H2S) which are measured ...
Positive effects of volcanic activity
... areas that surround a volcano. For example of this is mount pinatubo in the Philippines which erupted in 1991. ...
... areas that surround a volcano. For example of this is mount pinatubo in the Philippines which erupted in 1991. ...
Answers to the 13-2 two column notes
... Types of eruptions Quiet- Oceanic volcanoes commonly form from mafic magma. Mafic lava is rich is magnesium and iron and is usually dark in color. Because of mafic magma’s low viscosity, gases can easily escape. Eruptions from oceanic volcanoes, such as those in Hawaii, are usually quiet. Explosive- ...
... Types of eruptions Quiet- Oceanic volcanoes commonly form from mafic magma. Mafic lava is rich is magnesium and iron and is usually dark in color. Because of mafic magma’s low viscosity, gases can easily escape. Eruptions from oceanic volcanoes, such as those in Hawaii, are usually quiet. Explosive- ...
HST_CRF_04_02_03.qxd
... 1. Volcanic eruptions can be times stronger than the explosion produced by the first atomic bomb. 2. What is magma? 3. Magma that flows onto the Earth’s surface is called . 4. What is a volcano? ...
... 1. Volcanic eruptions can be times stronger than the explosion produced by the first atomic bomb. 2. What is magma? 3. Magma that flows onto the Earth’s surface is called . 4. What is a volcano? ...
The Italian Volcanoes In Italy, there are four active volcanoes, plus
... In Italy, there are four active volcanoes, plus other zones with volcanic activity of various types. Look at the blank map of Italy and mark the four volcanoes with a red dot. Write the name beside the dot then complete the table. ...
... In Italy, there are four active volcanoes, plus other zones with volcanic activity of various types. Look at the blank map of Italy and mark the four volcanoes with a red dot. Write the name beside the dot then complete the table. ...
plosky tolbachik volcano in kamchatka erupts after 40 years
... Tourists rushing to the area to view the once-in-40 years spectacle have been warned about the toxic gases. ...
... Tourists rushing to the area to view the once-in-40 years spectacle have been warned about the toxic gases. ...
Popular classification of volcanoes
... A super-volcano is a large volcano that usually has a large caldera and can potentially produce devastation on an enormous, sometimes continental, scale. Such eruptions would be able to cause severe cooling of global temperatures for many years afterwards because of the hugh volumes of sulfur and as ...
... A super-volcano is a large volcano that usually has a large caldera and can potentially produce devastation on an enormous, sometimes continental, scale. Such eruptions would be able to cause severe cooling of global temperatures for many years afterwards because of the hugh volumes of sulfur and as ...
Explosive and Non - Saint Peter School | Danbury, CT
... • Produce calm flows of lava • Can release large amounts of lava • Produce little ash or dust • Most of the rocks on the ocean floor come from these types of eruptions • Magma from these eruption have less silica • Magma is thinner and runnier Explosive • More destructive than a non-explosive Volcan ...
... • Produce calm flows of lava • Can release large amounts of lava • Produce little ash or dust • Most of the rocks on the ocean floor come from these types of eruptions • Magma from these eruption have less silica • Magma is thinner and runnier Explosive • More destructive than a non-explosive Volcan ...
Volcanology of Mars
Volcanic activity, or volcanism, has played a significant role in the geologic evolution of Mars. Scientists have known since the Mariner 9 mission in 1972 that volcanic features cover large portions of the Martian surface. These features include extensive lava flows, vast lava plains, and the largest known volcanoes in the Solar System. Martian volcanic features range in age from Noachian (>3.7 billion years) to late Amazonian (< 500 million years), indicating that the planet has been volcanically active throughout its history, and some speculate it probably still is so today. Both Earth and Mars are large, differentiated planets built from similar chondritic materials. Many of the same magmatic processes that occur on Earth also occurred on Mars, and both planets are similar enough compositionally that the same names can be applied to their igneous rocks and minerals.Volcanism is a process in which magma from a planet’s interior rises through the crust and erupts on the surface. The erupted materials consist of molten rock (lava), hot fragmental debris (tephra or ash), and gases. Volcanism is a principal way that planets release their internal heat. Volcanic eruptions produce distinctive landforms, rock types, and terrains that provide a window on the chemical composition, thermal state, and history of a planet's interior.Magma is a complex, high-temperature mixture of molten silicates, suspended crystals, and dissolved gases. Magma on Mars likely ascends in a similar manner to that on Earth. It rises through the lower crust in diapiric bodies that are less dense than the surrounding material. As the magma rises, it eventually reaches regions of lower density. When the magma density matches that of the host rock, buoyancy is neutralized and the magma body stalls. At this point, it may form a magma chamber and spread out laterally into a network of dikes and sills. Subsequently, the magma may cool and solidify to form intrusive igneous bodies (plutons). Geologists estimate that about 80% of the magma generated on Earth stalls in the crust and never reaches the surface.As magma rises and cools, it undergoes many complex and dynamic compositional changes. Heavier minerals may crystallize and settle to the bottom of the magma chamber. The magma may also assimilate portions of host rock or mix with other batches of magma. These processes alter the composition of the remaining melt, so that any magma reaching the surface may be chemically quite different from its parent melt. Magmas that have been so altered are said to be ""evolved"" to distinguish them from ""primitive"" magmas that more closely resemble the composition of their mantle source. (See igneous differentiation and fractional crystallization.) More highly evolved magmas are usually felsic, that is enriched in silica, volatiles, and other light elements compared to iron- and magnesium-rich (mafic) primitive magmas. The degree and extent to which magmas evolve over time is an indication of a planet's level of internal heat and tectonic activity. The Earth's continental crust is made up of evolved granitic rocks that developed through many episodes of magmatic reprocessing. Evolved igneous rocks are much less common on cold, dead bodies such as the Moon. Mars, being intermediate in size between the Earth and the Moon, is thought to be intermediate in its level of magmatic activity.At shallower depths in the crust, the lithostatic pressure on the magma body decreases. The reduced pressure can cause gases (volatiles), such as carbon dioxide and water vapor, to exsolve from the melt into a froth of gas bubbles. The nucleation of bubbles causes a rapid expansion and cooling of the surrounding melt, producing glassy shards that may erupt explosively as tephra (also called pyroclastics). Fine-grained tephra is commonly referred to as volcanic ash. Whether a volcano erupts explosively or effusively as fluid lava depends on the composition of the melt. Felsic magmas of andesitic and rhyolitic composition tend to erupt explosively. They are very viscous (thick and sticky) and rich in dissolved gases. Mafic magmas, on the other hand, are low in volatiles and commonly erupt effusively as basaltic lava flows. However, these are only generalizations. For example, magma that comes into sudden contact with groundwater or surface water may erupt violently in steam explosions called hydromagmatic (phreatomagmatic or phreatic) eruptions. Also, erupting magmas may behave differently on planets with different interior compositions, atmospheres, and gravity fields.