Ecuador's Tungurahua volcano is poised for a major eruption, a volcanologist said. Patricia Mothes, a US expert on volcanoes, said Wednesday the 5,023-meter volcano 135 kilometers southeast of Quito, "is preparing to generate, in days or weeks, a great eruption." She said that could mean pyroclastic flows - blasts of volcanic material "that descend at high speeds and burn everything in their way." Tungurahua, which has been active since 1999, has been freeing a high level of energy since Dec. 22, Mothes told The Associated Press in a telephone interview. "We have indications that there may be important volumes of magma which would be liberated in an eruption," she said.