10 Upton Drive, Wilmington, MA 01887
Toll Free 800-657-7704
Architectural Laboratory Water Treatment Marine Air Handling

cnc carving

Glaciologists and geographers should not trust any elevation that is indicated on maps of the Andes Mountains. The sources of their elevation data are never indicated, and these sources may differ from one another by several hundred meters. The critical work of a historian is often necessary to judge accuracy.
Considerable ground geodesy was done at the beginning of the 20th century by an Argentine-Chilean Comisión de Límites, which was charged to delimit the international border. The first edition in 1915 of the Carta Nacional de Chile (CNC), a set of maps at a scale of 1:500,000, used these data. Its last edition, with little modification, was published in 1945. Up to recent times, it was the best source for geographic place-names and for elevations north of lat 41°30'S. on the Chilean side and near the border. Near Santiago, Chile, the CNC was improved (more details and place-names, without modifying the elevations) in 1929 by W. Klatt and F. Fickenscher (KF). Their map at a scale of 1:250,000 was used by Chilean andinistas (mountaineers) up to 1956. On the Argentine side, very accurate maps at a scale of 1:25,000 of the Aconcagua group (lat 32°30'-32°50'S.) and of the glaciers in the Río del Plomo drainage basin (lat 32°55'-33°20'S.) were made by terrestrial photogrammetry (Helbling, 1919). Elsewhere, cartography of the Argentine Andes remained very poor up to recent times.
In the Andes Mountains near Santiago in normal years, small penitents about 10 cm high (micropenitents) can be observed as soon as late winter (Lliboutry, 1961). At 3,500 m, they reach about 50 cm tall in spring and 1 m in January (summer). The north-south dimension always remains 2 to 3.5 times smaller than the height of the blades as the blades melt. But at moderate elevations with the rise of the mean air temperature, the blades melt and penitents become mere "sun spikes." It is only at elevations higher than 4,500 m that penitents keep their shape indefinitely.
When the furrows of penitents reach bare soil, the penitents may be blown down; when the furrows reach glacier ice, the carving by local melting goes on into this ice (figs. 7, 8). Penitents on glaciers are, in general, 2-3 m high. Therefore, mountaineers (in Latin America, andinistas) avoid crossing any glacier, unless traveling in the east-west direction of the furrows. Nevertheless, the tallest penitents ever observed (5-8 m high) were not found on a glacier but on a snowdrift that had become firn. It was at 6,000 m on the north slope of Cerro/Nevado Ojos del Salado (lat 27°S.) in November 1949 (Belastín, verbal commun., 1952).

CNC Carving

Please Contact Us to discuss your cnc carving needs. You design it, we build it.

cnc carving

techniques | fittings
home | contact | sitemap | privacy | about | glossary cnc router, graduated cylinder, polypropylene, fume hood, plastic fabrication, rectangular tank, fretwork, pvc duct, plastic water tank, laminar flow hood, plastic machining, marine fish tank, plastic water storage tank, cylinder graduated reading, marine holding tank, acrylic fabrication, marine tank, graduated cylinder definition, polypropylene tank, plastic cone, cnc plastic router, petg plastic
cnc router | plastic fabrication | acrylic | manufacturing | water & air treatment | resources| web design