A new island emerged from volcanic debris in the Red Sea earlier this month—but scientists are still determining how long the island will stick around. According to news reports, fishermen reported on Dec. 19 that lava fountains reaching up to 90 feet were in the Red Sea, and scientists now believe that’s the day the island first sprang up. By Dec. 23, an island had appeared off the coast of Yemen. Volcanologist Erik Klemetti said that while he is surprised at “how quickly the island has grown,” people shouldn’t get too attached to it. “Many times the islands are ephemeral, as they are usually made of loose volcanic debris, so they get destroyed by wave action quite quickly,” Klemetti said.