Test 2 (Volcano Activities 4,5&7)

A tiltmeter is a technological device that can monitor the slope or incline of a volcano. It is used by organizations such as the United States Geological Survey (USGS) and the Hawaiian Volcano Observatory (HVO) to measure changes in the tilt of the volcano's surface. This information helps scientists monitor volcanic activity and predict eruptions.

Long term study of a volcano's behavior and past eruptions can provide valuable information about its patterns and tendencies. By analyzing historical data and monitoring changes in the volcano's activity, scientists can identify potential indicators of an impending eruption. Physical clues such as bulges of land, tilts, and earthquake measurements can also contribute to predicting volcanic eruptions. Therefore, the statement that long term study and analysis of a volcano's behavior can lead to a possible prediction of a volcanic eruption is true.

Monitoring a volcano cannot prevent an eruption. While monitoring can provide valuable information about the volcano's activity and potential signs of an impending eruption, it does not have the power to stop or prevent the eruption itself. Eruptions are natural processes driven by the buildup of pressure and other geological factors, and monitoring can only help in predicting and preparing for them, not preventing them.

Ash is the correct answer because it is the smallest tephra produced during volcanic eruptions. When ash particles are airborne, they can travel long distances from the eruption site and can cause mechanical failures in vehicles, such as helicopters or cars, if they get stuck in the motor.

When a volcano erupts, it releases various particles into the atmosphere, collectively known as tephra. Tephra includes different sizes of particles such as ash, lapilli, and volcanic bombs. The largest tephra is called a volcanic bomb. It is a large fragment of molten or semi-molten rock that is ejected from a volcano during an explosive eruption. These volcanic bombs are typically larger than 64 mm in diameter and can travel long distances before landing.

When loose ash from a volcano is soaked by rain, it can form lahars, which are volcanic mudslides. This occurs when the ash mixes with water, creating a dense slurry that can flow rapidly down the slopes of the volcano. Lahars are highly destructive and can cause significant damage to the surrounding areas, including burying buildings and infrastructure under layers of mud and debris. Therefore, lahars are the correct answer to the question.

Both A and B are physical clues that can predict that a volcano is preparing to erupt. When a volcano is about to erupt, it may swell, inflate, or bulge due to the accumulation of magma beneath the surface. Additionally, the slope or incline of the volcano may steepen or increase as the pressure from the magma builds up. These changes in the volcano's shape and structure are indicators that an eruption is imminent.

Volcanic eruptions impact climate in multiple ways. Volcanic products such as carbon dioxide, a greenhouse gas, can contribute to warming the atmosphere and accelerating global warming. Additionally, volcanic products like dust and ash can block sunlight, leading to a reduction in global temperatures. Sulfur and water vapor released during eruptions can generate rain containing sulfuric acid, which can have various effects on the environment. Lastly, volcanic products, specifically carbon dioxide, can accumulate near eruption sites and pose a suffocation risk to animals and people. Therefore, all of the given options correctly describe the impacts of volcanic eruptions on climate.

The correct answer is Both B & C. The ash distribution of the Mt. St. Helens eruption went both east and south. This means that the ash spread in two directions from the volcano, covering areas to the east and south of the eruption site.

False. While a higher VEI indicates a larger and more explosive eruption, it does not necessarily mean that more deaths occurred. The number of deaths depends on various factors such as the proximity of human settlements to the volcano, the preparedness and response of the affected communities, and the effectiveness of evacuation measures. Therefore, it is possible to have a high VEI eruption with relatively few deaths, or a low VEI eruption with significant loss of life.

The statement is false because the majority of the ash from the Mt. St. Helen's eruption blew towards the east, affecting areas in the United States such as Washington, Idaho, and Montana. While some ash did reach Canada, it was not a significant amount compared to the impact on the US.

Volcanic eruptions release various gases and compounds into the atmosphere, such as water vapor, sulfur, hydrogen chloride, and nitrogen. However, fluorine is not typically emitted during volcanic eruptions. Fluorine is a highly reactive element that is not commonly found in volcanic emissions. Therefore, the correct answer is fluorine.

Not all volcanoes are monitored with seismographic equipment to detect signs of impending eruption. While seismographic equipment is commonly used to monitor volcanic activity, it is not universally available or used for all volcanoes. Monitoring methods can vary depending on the location and resources available, and may include other techniques such as gas monitoring, thermal imaging, and ground deformation measurements. Therefore, it is not true to say that all volcanoes are monitored with seismographic equipment.

The hint on page 56 suggests that physical clues alone cannot definitively predict a volcanic eruption. While physical clues such as the tilt of the volcano, swelling, and earthquake measurements can provide valuable information about volcanic activity, they are not always accurate indicators of an imminent eruption. Other factors such as gas emissions and changes in volcanic activity patterns also need to be considered for a more reliable prediction. Therefore, the statement that physical clues can definitely predict a volcanic eruption is false.

When sulfur combines with oxygen and water vapor, it creates acid rain. Acid rain is formed when sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere from sources such as volcanic eruptions and power plants. These pollutants react with water vapor in the air to form sulfuric acid (H2SO4) and nitric acid (HNO3), which then fall to the ground as acid rain. Therefore, the correct answer is water vapor.