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Show Lightning Caused Fires BLM installs Lightning Detection System (:." M j 7 J v -. p i - J ' aiMfarMfflfriYflwdtotiiiflfciiyi ni'aiia nwinfruaMiaEfliiini itMlhrtiMW.aftafenitfigntiliwW . Air CHECK FOR FIRES - Sally Roberts, BLM lightning detection technician, sends out strike locations - pinpointed to within one mile - to agencies responsible for providing fire protection. The strike locations can then be checked by air or ground patrols to see if a fire has been started. azimuths of storm centers to the coordinating station where the data is processed and interpreted, then returned to the detection station is usable form, with cloud-to-ground strikes pinpointed to within one mile in the 250-mile radius covered by the station's electronic scanning units. 3 minute response With ALDS, strike data is sent to the coordination center within three minutres of the occurrence and strike locations are relayed back to detecting stations within five minutes. Then the strike locations can be checked by air or ground patrols to see if a fire has been started. If the location is not on BLM-managed BLM-managed land, the information in-formation is given to the agency responsible for providing fire protection such as the Forest Service, Park Service, or the Utah State Division of Forestry. stations are in Grand Junction, Junc-tion, Colorado, Lewistrown and Miles City, Montana; and Rock Springs, Wyoming. The new Rocky Mountain coordinating center is in Grand Junction. The Cedar City station reports to Elko those lightning strikes detected to the west and those to the east are reported to Grand Junction. "Dry" Lightning Although radar is capable of picking up large, moisture-laden thunderstorms, thun-derstorms, unlike the ALDS it cannot detect "dry" lightning. Since the moisture asosciated with a thunderstorm thun-derstorm is often sufficient to extinguish any fires which might start, these storms rarely present the most severee fire hazard. Hot, crackly dry lightning, however, poses a far more serious and unpredictable threat. Thus, the ALDS, coupled with radar, can provide a comprehensive detection system. Some 36 percent of all wildfires on public lands in the 17 western states are caused by lightning and, according to many estimates, one lightning strike out of 10 produces a fire. Because it freequently occurs in remote areas, where detection and containment con-tainment can be slow and tortuous, a lightning-caused fire is the most costly type and does the most damage. In the years 1970 to 1975, lightning-caused wildfires on BLM-administered lands burned approximately 3.6 million acres and destroyed resources valued at 61.5 million. 10-year history According to George "Butch" Kasper, BLM fire control officer for Utah, there have been 1,131 lightning-caused fires on BLM-manged lands in Utah during the past 10 years. "Out of our more than 90 fires this year, more than 65 percent have been lightning-caused," lightning-caused," said Kasper. "We can't control the number of fires started by lightning, but we can expect a reduction in damage and acreage burned with the help of the Automatic Lightning Detection System," he said. One of the most critical factors in fire control is time and now there is a detection system in operation covering millions of acres in the West that greatly reduces the time to locate and control fires caused by lightning. Called the Automatic Lightning Detection System (ALDS), it was designed and built for the Bureau of Land Management (BLM) by the University of Arizona in 1974. Tested in Alaska in 1975 and 1976 with excellent results, the system was installed in 1977 in the Great Basin, including a detection station in Cedar City. Other stations were installed in Elko, Nevada; Susanville, California; Vale, Oregon; and Shoshone, Idaho, reporting data to a coordinating coor-dinating center in Elko. A joint effort of BLM, Forest Service and National Park Service, the system costs one-tenth that of air patrol fire detection systems. Direction finder Heart of the detection system is a simple and relatively inexpensive magnetic direction finder. Basically, the instrument senses the magnetic field created by a lightning strike as it returns from the ground to the thundercloud where it originated, while rejecting cloud-to-cloud discharges. Information transmitted by the direction finder is coupled with data from radar or a second direction finder to plot by triangulation the strike's location. Detection stations send The Cedar City station is located at the Interagency Fire Center east of the airport and directed by Lloyd Benson, chief dispatcher of the Forest Service. Four temporary BLM and two Forest Service employees were trained by Benson for the fire season. They work shifts, keeping the lightning detection system in full operation 24 hours a day during the season of highest danger. Coverage doubled According to Benson, the system has proved so successful suc-cessful that coverage has been doubled this summer. New ALDS detection vkt hi r A M I iifn' - , T" CHECKING LIGHTNING STRIKES - LaDawn Allen (left), dispatcher at Cedar City Interagency Fire Center, checks lightning strikes on plotter machine finder chart while Sally Roberts, lightning detection technician, prepares to transmit information to coordination center by teletype. |