Better knowledge of ocean bathymetry, island and coastal topography, and the transfer of energy between slide blocks and water also contributed to more accurate modeling. Studies of landslide-induced waves show that they travel at different speeds and interact more across long distances, leading to smaller wave height far from their sources. Tsunami modeling has also advanced considerably since 2001. In addition, geomorphologists found, via slope stability analysis, that the potential collapse volume is much smaller than was simulated by the 2001 paper. Ocean floor mapping surrounding the Canary Islands, however, indicates that collapses instead occur in incremental or piecemeal fashion. The Canary Islands “mega-tsunami” scenario assumed a single, coherent, massive collapse block that reached a high velocity very quickly. This scenario made headlines in the media, which inaccurately depicted a huge wave devastating New York City.īut can collapses actually generate these “mega-tsunami” far from their sources? Subsequent research casts doubt on this idea. In 2001, an academic paper suggested that collapse of La Palma could result in tsunami waves up to 25 m (about 80 feet) high along the east coasts of North and South America. From this understanding grew a notion that collapsing volcanoes-particularly in the Canary Islands-could generate ocean-wide “mega-tsunami.” The eruption style is similar to Hawaiian eruptions, and both locations share the potential for flank collapse and tsunami.īasaltic ocean islands, such as the Island of Hawai‘i and the Canary Islands, tend to experience catastrophic landslides every few hundred thousand years-a discovery first made by USGS Hawaiian Volcano Observatory Scientist-in-Charge Jim Moore in the early 1960s! A significant portion of an island is removed during collapse and has the potential to displace tremendous amounts of seawater, generating local tsunami waves that are thought to be over 100 meters (300 feet) high. “Volcano Watchers” are probably aware that an eruption began on La Palma in the Canary Islands on September 19. Lava deltas are built by the accumulation of lava near the base of the sea cliff at an ocean entry. One of the lava flows is entering the ocean, creating new land called a lava delta. This aerial photo, courtesy of Radio Televisión Canaria, shows lava flows that are being generated by a fissure eruption upslope on La Palma. Like Hawaiian volcanoes, La Palma typically erupts lava flows. La Palma is a basaltic shield volcano in the Canary Islands.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |