Made by Lava

October 15, 2018

Jim McMahon/Mapman

This summer, the island of Hawaii grew by at least 120 acres. In May, the volcano Kilauea began spewing lava during a new eruption. Slow-moving rivers of lava have since seeped out of cracks in the volcano’s side. The lava has destroyed more than 700 houses on its 25-mile trip downhill to the ocean.

Much of the lava spilled into the sea, adding to the island’s coastline. But some of the magma flowed underground. (Molten rock is called lava after it reaches the Earth’s surface.) The magma flowed under the seafloor. Then it burst through the seafloor in late July and piled up to create a tiny island. But as the lava piled up, it became connected to the main island and is now a peninsula!

YOUR TURN

Now, the tiny island (above) is attached to the mainland. But in July, it was roughly a circle with an area of 600 square feet. What was its diameter? Record your work and answer on our Numbers in the News answer sheet.