Hawaii’s Big Island has declared a state of emergency following lava flow threatening its residential areas. Given lava’s 1000 degrees Celsius temperature, and uneven flow, lava is notoriously hard to protect human life against. Measures to protect civilians therefore have historically involved evacuating cities and towns.
Nevertheless there have been human interventions in the past in order to curtail the flow of lava. During World War II, Hawaii’s Mauna Loa was bombed, with the intention being that the lava tubes that carried the lava would break and prevent the flow of lava. In reality, and perhaps predictably, the lava instead filled up the cavities created by the flow. Luckily, the lava stopped flowing anyway and the residents were saved.
More successfully, on the Icelandic island of Heimaey, a flow of lava was stopped by blasting cold water cannons at the lava, to slow its movements. So what’s the caveat? It took 6.8 billion litres of water and took 5 months, after which large portions of the island were destroyed.
Earth sciences and geography applicants would note that given humans have a poor success rate at preventing lava flow, prediction and mapping of volcanic movement are key to saving human lives and understanding more about how the earth’s crust operates. Engineering applicants should note these different attempts at human solutions to physical geographic problems, and think on the pros and cons of these solutions to lava flow.