A Northwestern University seismologist – Suzan van der Lee – has been ‘looking inside the Earth’, focusing on the Mauna Loa eruption and what science can learn in terms of predicting future volcanic activity. Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean.
Currently, Mauna Loa (the world’s largest active volcano) is erupting for the first time since 1984, as the BBC has reported. The report indicates that lava is flowing down the side of the volcano at a temperature of 1,000 degrees Celsius. This brings with it the additional risks of ashfall, and destructive earthquakes.
While ash is an issue, it is the quantity of lava that is of greatest interest to the researchers. Van der Lee says: “Each volcano is unique. The Hawaiian volcanoes are not known for the amount of ash that they erupt. It’s mostly the lava, which is gently flowing. It’s not a very violently erupting volcano. Even though there was originally a warning for ash — which can affect lungs, crops and water supply — It seems most of the danger for people living on the rim of the Hawaii island at the lower elevations was the potential for lava flow.”
One reason why researchers know about the distinctive features of Mauna Loa is based on advances with tracking systems. Technology has enabled improved predictions and communication about Mauna Loa’s eruption.
Van der Lee explains in a statement sent to Digital Journal: “Since a journey inside the Earth is not physically possible, we use data and technology, for example, recorded seismic waves to see what’s happening inside the Earth. It’s as amazing that we can look inside the Earth as it is we can look inside a human body with an MRI.” Through the technology it is possible to create tomographic images (images using seismic waves to virtually section the Earth’s interior).
A key means of monitoring is by using seismometers, installed round the island to pick up increasing activity. This reveals considerable details since as magma accelerates its way to the surface, it needs to break solid rock. That creates seismic waves that are recorded and tremors.
According to Van der Lee: “That’s a very important observational tool. Other ways are geodetic instruments, like tilt meters of Global Navigation Satellite Systems (GNSS), that constantly measure the shape of volcanoes. If that shape is expanding left, right or up, that could be an indication that something is going on underneath and trying to make room for magma coming to the surface. Other instruments measure gases that routinely escape through fissures and cracks and vents and so on.”
These approaches have been used elsewhere in the world. For example, assessing a volcanic island in Tonga which has erupted in a very unusual and uncharacteristic way. Van der Lee’s research on observed seismic waves helps researchers to better understand volcanoes and draw insights about the structure of the Earth’s interior.
