LEAD:
The Nighttime Journey of Coral Larvae: For four nights starting one day after each new moon during a period of about 4 months - this year, from May through August, coral larvae are on the move off Maui. Corals are small colonial animals that secrete hard outer skeletons. One of the principal corals for building reefs in Hawaii, "rice coral" (Montipora capitata), releases packets of eggs and sperm at about 9 p.m. each evening during these months. The packets rise to the ocean's surface and float along-by the millions-in surface currents until the fertilized eggs, or larvae, sink and start to grow on rocky areas. Scientists can predict to the hour when the reef-building coral off Maui will spawn, but no one knows where the floating coral larvae go. So from June 29 to July 5, scientists from the U.S. Geological Survey, the University of Washington, the University of Hawai'i, the Hawai'ian Division of Aquatic Resources, and the Maui Ocean Center conducted an unprecedented experiment to track the elusive coral to find out why certain reefs off West Maui are doing well and why others are doing poorly. The scientists used underwater tripods, much like lunar landers, to monitor temperature, water clarity, waves, and currents. At the same time, satellite-tracked drifters were released at night to float along with the larvae, and the scientists monitored the drifters' positions on radio frequencies. Reproducible photos are available at http://coralreefs.wr.usgs.gov/press.html (Carolyn Bell, 703-648-4463, cbell@usgs.gov )
Frogs, Fish and Fire: In order to fully understand fires and the effects on the environment, we need to broaden our thinking. Frogs and fishes don't normally come to mind as being vulnerable to the effects of fire – after all, they live in water. But scientists from the USGS have conducted research that indicates these species may be remarkably sensitive to fire-induced habitat changes. After all, terrestrial and aquatic landscapes are intimately linked. In recent years, fires have been record setters. There has been devastating property damage and horrific images of animals and people fleeing from wildfires. For more see http://www.usgs.gov/public/press/public_affairs/press_releases/pr1763m.html to learn about this interesting research. (A.B. Wade 703-648-4460, abwade@usgs.gov)
FEED:
Does Columbia River Dredging Displace Sturgeon Or Not? Navigable Waterways and Sturgeon: White sturgeon are the largest freshwater fish found in North America, some reach lengths of 18-20 feet. They are also long-lived, with some older than the oldest dams on the Columbia River. The U.S. Army Corps of Engineers, who is responsible for maintaining the navigation channel in the Columbia River, often discharge dredged materials back into the river. While white sturgeon populations in the lower Columbia River are probably the healthiest stock of sturgeon in the United States, even supporting limited commercial and sport fisheries, there is concern about the effects of dredging on this species. Private and public sector opinion on the impact the dredging has on the fish is varied. The U.S. Geological Survey is working with the Corps of Engineers to find out just what these fish do while dredging is done. Since August 2002, the USGS has been using an acoustic telemetry system to continuously monitor movements of individual white sturgeon in real time. Analyzing fish movements before, during, and after dredging occurs will provide proof, rather than opinion, to assist decision makers regarding dredging activities and their effects on sturgeon. Mike Parsley (michael_parsley@usgs.gov) 509-538-2299.
Eruptions "R" US: July 9th marks the 50th anniversary of the sudden and dramatic eruption of Crater Peak, the active vent on Mount Spurr volcano in Alaska. The eruption caused major disturbances to air traffic and an eerie, premature twilight over a large portion of the State. Since then, volcano monitoring has improved substantially, helping save lives, health and property. By the summer of 1992, when three closely spaced similar eruptions occurred at Crater Peak, scientists at the Alaska Volcano Observatory were able to warn communities and the aviation industry before the eruption. Residents were now prepared as the ash cloud blanketed Anchorage, Prince William Sound, and the southeastern shoreline of the Gulf of Alaska. The greatest hazard posed by eruptions is airborne ash.. Volcanic ash consists of tiny jagged particles of rocks, minerals and natural glass; it is abrasive, mildly corrosive, and conducts electricity when wet. And because of the size and frequency of their eruptions, Alaskan volcanoes pose a significant threat to aircraft because they intersect North Pacific air routes. This air route, directly over the volcano-laden Aleutian arc carries nearly 20,000 people and millions of dollars in cargo every day. See http://www.avo.alaska.edu for pictures and information. (Catherine Puckett, 707-442-1329, catherine_puckett@usgs.gov )
SEED:
A Cool Thought for Mid-Summer--Alaska's glaciers hold billions of gallons of fresh water. In fact, worldwide, there is six times more fresh water tied up in glaciers than all of the other fresh water on earth combined. The Bering Glacier is the largest glacier in Alaska, and glaciers cover about 5 percent of Alaska's land surface. Images of Alaskan glaciers are available online at http://www.usgs.gov/features/glaciers2.html , and glacier FAQs and fun facts are at http://ak.water.usgs.gov/glaciology/FAQ.htm .
Summer science quiz--fun facts. For more fun earth science facts visit the USGS at ... http://www.usgs.gov/sci_challenge.html
- What is the single longest river in the world? The Nile River in Africa at 4,160 miles in length.
- What is the highest point above sea level in the United States? Mt. McKinley, Alaska, at 20,320 feet above sea level.
- Where is the lowest point in the United States? Bad Water in Death Valley, California, at 282 feet below sea level.
- What are the most eastern, western, southern and northern points in the United States? The westernmost point is West Point of Amatignak Island, Alaska. The northernmost point is Point Barrow, Alaska. The southernmost point is the southern tip of the island of Hawaii. The easternmost point is Pochnoi Point, Semisopochnoi, Alaska, because it lies east of the 180-degree longitude.
- Are there more earthquakes during the hot summer? There is no such thing as "earthquake weather". Statistically, there is an equal distribution of earthquakes in cold weather, hot weather, rainy weather, etc. Furthermore, there is no physical way that the weather could affect the forces several miles beneath the surface of the earth. The changes in barometric pressure in the atmosphere are very small compared to the forces in the crust, and the effect of the barometric pressure does not reach beneath the soil.