Sharon welcomed the listeners and talked about the importance of water in life and life in water. She said that it is imperative for everyone to realize the importance of water, to drink plenty of water and to carry water with them if they are unsure of a water source. Dehydration, or lack of water, is out of control in our world and causes or contributes to ailments from allergies to obesity.
Guest: Dina Venezky
Dina Venezky (Menlo Park, CA), US Geological Survey. "How the USGS Communicates Volcano Information to the Public."
Dina Venesky works for the USGS in Menlo Park, California, with a program that offers education about volcanoes and volcano hazards.
Volcano hazards include gases (CO2 and others), steam, air pollution, water pollution, water heating, and lava movement. Volcanism is responsible for great changes in the landscape and the movement of continental plates. It was volcanism that ended the Earth's "Snowball Period" when it completely froze over, about 600,000,000 years ago.
"Plates" are large independent, contiguous masses, usually of granite. There are large plates and small plates. The US monitors plate movements and movements of the Earth's surface (ground deformation and swelling) 24 hours a day to attempt to predict impending eruptions and earthquakes (plate and fault line slippage). Not all quakes are volcanic but a buildup of underground magma (lava) can definitely cause quakes.
People too often choose to live and build near volcanoes because they are very pretty and often provide geothermal energy and heat. But they can be deadly.
California has many volcanoes. Shasta, Medicine Lake, Lassen and Long Valley (Mammoth Mountain) are the major ones and are all considered dormant or recently active. All of them could pose a serious threat to surrounding populations (Mt Konocti, near Clear Lake, is also a major volcano but it last erupted 10,000 years ago).
In Hawaii, the major active volcanoes, Moana Loa, Kiluea and Haleakala, are protected by National Parks. However, the highest point in Hawaii, Mauna Kea, is unprotected, and Diamond Head, a volcanic crater, is immediately adjacent to Honolulu. Mauna Kea last erupted 4,500 years ago while Diamond Head last erupted 150,000 years ago.
Volcanoes in Alaska and the Pacific Northwest tend to be heavily glaciated. It was the destruction of a glacier, and of Spirit Lake, in the 1981 Mt. St. Helens eruption that caused the major "lahar" flooding of the Toutle River responsible for millions of dollars of property damage.
Categories: Ecology and the environment, 2009