original_query: What is the purpose of spraying water on lava flows in Hawaii and on Meldfell?
query: What is the purpose of spraying water on lava flows during the Eldfell eruption and in other locations like Hawaii?
answer: The purpose of spraying water on lava flows, as demonstrated during the Eldfell eruption and in previous attempts in Hawaii, is to cool and solidify the advancing lava flow to slow its progression and prevent damage to infrastructure, such as harbors or towns.