Aceh, Indonesia. 13th Sep, 2017. Geophysicists observe a natural limestone cave located at Lhoong district in Aceh, Indonesia, on Sept. 13, 2017. Researchers analyzed sand deposits from a limestone cave near the provincial capital of Banda Aceh and used their findings to create a detailed chronology of the region's tsunamis. Credit: Junaidi/Xinhua/Alamy Live News

- Image ID: K723RF
Aceh, Indonesia. 13th Sep, 2017. Geophysicists observe a natural limestone cave located at Lhoong district in Aceh, Indonesia, on Sept. 13, 2017. Researchers analyzed sand deposits from a limestone cave near the provincial capital of Banda Aceh and used their findings to create a detailed chronology of the region's tsunamis. Credit: Junaidi/Xinhua/Alamy Live News
Xinhua / Alamy Stock Photo
Image ID: K723RF