Figure 14.7

Mafic lava formations. (A) This lava lake is on Erta Ale volcano, in the Danakil depression in Ethiopia, one of only five volcanoes in the world that have a persistent lava lake. (B) Mafic lava erupted beneath the ocean forms pillow lava. Seawater quickly cools the lava, and as a result, it takes a rounded form resembling pillows (illustrated in the inset). West Mata volcano, shown in the photo, was discovered in May 2009. It is about 1,200 m (4,000 ft) underwater, some 200 km (125 mi) southwest of Samoa in the Pacific Ocean.