The popular image of a volcano is that of a solitary, graceful, snowcapped cone, such as mount hood in Oregon or japan’s Fujiyama. These picturesque, conical mountains are produced by volcanic activity that occurred intermittently over thousands, or even hundreds of thousands, of year. However, many volcanoes do not fit this image. Cinder conder cones are quite small and from during a single eruptive phase that lasts a few days to a few years. Other volcanic landforms are not volcanoes at all. For example, alaska’s valley of ten thousand smokes is a flat-topped deposit consisting of 15 cubic kilometers of ash that erupted in less than 60 hours and blanketed a section of river valley to a depth of 200 meters(600 feet).