Author Archives: laceymarie1987

How does a thermocouple measure the temperature of lava without melting?

A thermocouple works on the principle that the electrical resistance at the point where two wires of different composition join, is very sensitive to the temperature. So…a thermocouple consists of two wires joined to an electrical source. Current passes through … Continue reading

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How do volcanoes help scientists learn about the Earth’s interior?

The deepest samples of the Earth’s interior brought up from drill holes come from a depth of 12 km . . . . volcanoes provide direct samples of the Earth’s interior from much greater depths . . at least 100 … Continue reading

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How do Volcanologists predict volcanic eruptions?

The prediction of volcanic eruptions is difficult because, to be of practical use, they must be made before eruptions! Its a lot easier to see patterns in monitoring data after an eruption has occurred. But great progress has been made … Continue reading

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What tools do Volcanologists use to study volcanoes?

Volcanologists use many different kinds of tools including instruments that detect and record earthquakes (seismometers and seimographs), instruments that measure ground deformation (EDM, Leveling, GPS, tilt), instruments that detect and measure volcanic gases (COSPEC), instruments that determine how much lava … Continue reading

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How does magma form and what makes it erupt?

Magma forms from the partial melting of mantle rocks.  These little blobs of melt migrate upward and coalesce into larger volumes that continue to move upward. As they rise, gas molecules in the magma come out of solution and form … Continue reading

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Why is lava so hot?

Lava is hot for two reasons: It’s hot deep in the Earth (about 100 km down) where rocks melt to make magma. The rock around the magma is a good insulator, so the magma doesn’t lose much heat on the … Continue reading

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Why is lava different colors?

The color of lava depends on its temperature. It starts out bright orange (1000-1150 C). As it cools the color changes to bright red (800-1000 C), then do dark red (650-800 C), and to brownish red (500-650 C). Solid lava … Continue reading

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