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Management Responses to Volcanic Hazards (Preparedness (The state of…
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Protection
Long Term
Shelter from ash
Provide shelter for people, pets, livestock and machinery
Tiny abrasive ash particle are easily inhaled and harmful. They are so small they can get into the most tightly sealed buildings and machinery.
Extensive ash fall can cause power failures and disturb water, transportation, and communication systems.
Have survival and clean-up resources on hand such as dust masks, extra medications, plastic sheeting, and heavy-duty tape
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Lava
Using water
One of the most successful lava stops came in the 1970s on the Icelandic island of Haimey. Lava from the Eldfell volcano threatened the island's harbour and the town of Vestmannaeyjar.
For almost five months in 1973, frigid sea water was blasted through cannons towards the advancing lava. As the water hit the superheated rock, it turned into steam, allowing the lava's heat to dissipate.
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This only works if conditions are right - the lava was slow moving and there was an inexhaustible supply of seawater
Build a barrier
At Mount Etna, an eruption in March 1983 threatened three towns. Barriers of rock and ash were constructed in an attempt to divert the lava
One of the first barriers, 18m high and 10m wide, was overrun, but a second barrier blocked lava from moving further west.
Short Term
Road signs
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These rely on people being able to move; it doesn't really provide any protection, it just tells people what to do.
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Bombing lava tubes
Lava tubes are cooled and hardened outer crusts of lava which provide insulation for the faster-flowing, molten rock inside.
In theory, bombs would destroy the lava tubes, robbing lava of an easy transport channel and exposing more of the lava to the air, slowing and cooling it further. But in practice, while bombs created craters in parts of the tubes, they were soon filled again by the lava. Hilo was instead saved when Mauna Loa stopped erupting.
Later tests by the US Air Force suggested newer, larger bombs could make more of a difference if they were targeted at the most vulnerable sections of the flow.
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Concrete trenches
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Better to work on prediction, rather than protection
Prediction
Short Term
The USGS Volcano Hazards Program monitors volcanoes to detect signs of change that forewarn of volcanic reawakening.
Monitoring includes several types of observations (earthquakes, ground movement, volcanic gas, rock chemistry, water chemistry, remote satellite analysis) on a continuous basis.
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Comparing the data with results from past volcanic events, to make predictions on changes in volcanic activity and determine whether and when a volcano might erupt in the future
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Deformation
Magma accumulates beneath the ground, causing the surface above to inflate, the slope will usually tilt away from the center of uplift. Conversely, if the ground deflates due to magma draining away, the slope will tilt toward the center of subsidence.
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Gas and Water
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Scientists can learn a lot about changes to the magma system within a volcano by
1) measuring changes in the emission rate of certain key gases, especially sulfur dioxide and carbon dioxide
2) collecting and analyzing water samples to look for chemicals, such as hydrogen chloride and hydrogen fluoride (both easily dissolve in water) that indicate volcanic gas has been filtered by the water.
Carbon dioxide (CO2) gas separates from magma deeper than other volcanic gases. If increased CO2 levels are detected at the surface, that may indicate new magma is entering the volcanic system
Sulfur dioxide (SO2) is released from a volcano when magma is relatively near the surface. If SO2 is detected at a non-erupting volcano, it could be a sign that it will erupt soon
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Heat/Thermal Monitoring
Some volcanoes have thermal features such as steaming vents, geysers, hot springs, lava flows, or lava domes. Surface temperature changes at these thermal features sometimes occur before a volcanic eruption.
Long Term
Assessment of the types of hazards posed by the volcano and the frequency at which these types of hazards have occurred in the past. The best way to determine the future behavior of a volcano is by studying its past behavior as revealed in the deposits produced by ancient eruptions
Hazard Maps
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Good way to educate locals and tourists about the dangers that the volcano may pose should it erupt. It can also show people safe areas to shelter in the event of an eruption.
At temperatures of about 1,000C (1,832F), lava destroys whatever it touches. Its path is notoriously hard to predict.
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Prediction of volcanic activity can vary based of each spewcific volcano. Although, generally careful monitoring and comparison to historical data is used most frequently. Short - term prediction of volcanic eruptions involves monitoring the volcano to determine when magma is approaching the surface and monitoring for precursor events that often signal a forthcoming eruption. So although monitoring occurs over a long period of time. It is classified as a short term method since you are keeping a beady eye on short term changes in seismology, gas composition and rock structure
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