- SPECIAL REPORTS
- THE MAGAZINE
New Year's at the South PoleNot many people can say they celebrated the turn of the millennium in a garage at the South Pole. A group of about 220 people can, however. National Science Foundation researchers, construction workers and support staff joined at the Amundsen-Scott South Pole Station in Antarctica to celebrate the end of a year, the beginning of a millennium and the relocation of the South Pole.
The group had been there for months performing GPS measurements on the icy region to determine the new location of the South Pole, which is known to move every year. The ongoing collection of GPS data at the South Pole provides an accurate reference for other geopositioning activities in the region as well.
Although the South Pole itself is stationary, the 2-mile thick ice sheet covering the rocky continent slips gradually, moving about 30' a year, forcing the South Pole seaward about 10 m. At this rate, the current South Pole marker will drop into the sea in about 140,000 years.
The methods used to determine the location of the Pole have radically changed since the first measurement by Roald Amundsen on Dec. 14, 1911. That first survey, and its confirmation a month later by Robert F. Scott, used observations of the sun. The sun is above the horizon six months of the year when at the geographic location for the South Pole. During a 24-hour period, the sun moves parallel to the horizon a complete rotation around the Pole, gradually rising to its highest angle above the horizon on December 21. Amundsen and Scott used sextants or similar instruments to measure the angle of the top edge of the sun above the horizon. When the angle or altitude above the horizon was equal, they stood at the geographic location for the South Pole. This method is accurate to about Â±300 m.
From 1975 through 1991, the U.S. Geological Survey (USGS) deployed and operated a continuous Doppler satellite measurement and positioning system in the vicinity of the South Pole at the United States research base in Antarctica. In December 1991, GPS replaced the Doppler satellite observations with more accurate measurements. The estimated accuracy with the use of the Doppler satellite was about 1 m; GPS accuracy is a few centimeters.
The research group held a brief ceremony for the relocation by hammering a rod into the ice at the new location. Shop workers designed an ornamental medallion for the stake during the three-month-long winter night at the Pole. That day, in subzero temperatures and under the light of 24-hour sunshine, the group celebrated with champagne and a live band. Larry Hothem of the USGS, who planted the marker, summed up the day. "To say the least, it was quite a memorable event. For certain, I will never forget where I was on New Year's Day 2000!"
Sizing Up KilimanjaroGPS technology has now measured two of the highest points in the world: Mount Everest in Asia and Kilimanjaro in Africa. During an eight-day expedition in September 1999, three independent teams of European and Tanzanian experts completed the endeavor at Kilimanjaro, the "Mountain of the Evil Spirit." They not only determined the extinct volcano's value, but also proved the accuracy of GPS technology to the millimeter.
While taking measurements on the mountain, another team marked additional positional and height points in the near vicinity of the extinct volcano Kilimanjaro, enabling the Tanzanian national survey grid to be linked to the International Terrestrial Reference Frame (ITRF). The geographical positional coordinates (B, L) and the ellipsoidal height (h) of the most elevated point measured on Uhuru Peak, the volcano's highest peak, served as the basis for determining the geoid height in the Earth Geoid Model 96 and for calculating the orthometric height above mean sea level.
Since sickness is nearly inevitable at elevations of 4,000 m, five mountain guides attended a one-day training session to perform the measurements without expert assistance, should the need arise. A Leica GPS500 station (Leica Geosystems, Norcross, Ga.) at Moshi on the southern foot of Kilimanjaro provided permanent data throughout the expedition. Measurements were taken at six additional locations. The observation times ranged from one to 24 hours-short periods for such a prestigious accomplishment!
TSPS Supports Adopt-A-Map ProgramIn the near future, Texas will be completely online-maps of Texas, that is. The Texas Society of Professional Surveyors (TSPS) has endeavored to scan all documents and maps of the state through an Adopt-A-Map project. The maps will be available to the public on the Internet. Texas Land Commissioner David Dewhurst launched the project to preserve and retire the original historic records and maps housed in the Texas General Land Office.
About 400 maps of the state, its counties, some cities and old districts are listed for adoption. About 40 to 50 of these maps are the oldest, largest and most historical, including Spanish, Mexican, Republic of Texas and state records that document the settlement of Texas dating back to the 1800s. Many of the records and maps have ornate writing and artwork created by scribes and draftsmen.
So far, TSPS Board of Directors voted to donate $5,000 to the project and various chapters pledged approximately $10,000. Visit the TSPS website at www.tsps.org for more information.
SIR Controversy in New MexicoA 10-year practice may be eliminated for New Mexico surveyors if the New Mexico Professional Surveyors (NMPS) gets what it wants. In July 1999, the NMPS Board of Directors proposed the collective deletion of Inspection Report Surveying and Surveyor Inspection Reports (SIRs) from the state's Minimum Standards as a discipline of surveying. Inspection Report Surveying and SIRs, narrative reports often accompanied by a sketch of a tract of land, were recognized as a surveying activity in November 1989. Title, abstract or escrow companies and lending institutions use SIRs for exclusive use in determining such things as insurability or value of land. And though the New Mexico Minimum Standards currently states that SIRs are not surveys, the NMPS believes title companies, real estate agencies and others deceive the public by representing SIRs as full boundary surveys. Current NMPS President Steven Frank said the organization believes that if a SIR is not a survey, it should not appear in the Minimum Standards for Surveying. Richard Smith, a driving force behind the inclusion of SIRs in the Minimum Standards in 1989, currently supports the deletion since he believes their purpose has been abused by title companies.
At a Sept. 16, 1999, meeting in Santa Fe, the majority of New Mexico surveyors present agreed with the deletion proposal set forth by NMPS. Land title industry representatives strongly supported SIRs, arguing that survey protection is necessary in all title insurance policies, an argument NMPS believes is not valid, since SIRs are supposed to be used exclusively to assess title insurance and financing; protection comes from full surveys. Title representatives also said that requiring property boundary surveys would slow down real estate transactions and increase closing costs.
The issue has been discussed before but never put before the Board for deletion. The Board of Directors forwarded their recommendations to the Board of Registration, which held three hearings throughout the state. The Board maintains that SIRs are not property boundary surveys. The issue has been postponed until July of this year.