A cross-section of periglacial slopes and valleys that shows several alternations of slope stratifications is called stratified slope waste deposits in some literature. These slopes consist of alterna
ting deposited fine and coarse sediments that are oriented downhill. Trombotto (1991) presented different possible genesis for such structures in the periglacial slopes of the Central Andes.
The time system in which the determination of mass balance is based on the identification of successive Annual minima, and for seasonal balances Annual maxima also, in the mass of the glacier or a par
t of the glacier. In field work, Annual mass balance is determined by the detection of two successive summer surfaces, usually at individual observation sites. In the ablation zone, the earlier summer surface has disappeared by the time the later one is observed, but its vertical position is known from earlier observations. For seasonal balances, it is not possible to determine the Annual maximum of mass with a single field survey that can be scheduled to coincide only roughly with the expected date of the maximum. Thus, in the stratigraphic system, seasonal balances by the glaciological method are actually measured in a combined system. Continuously recording sensors, such as snow pillows and sonic rangers, can yield accurate stratigraphic-system estimates of seasonal balances at single points, but they are not in wide use. The Annual extrema of mass may be reached at different times at different sites on the glacier. Glacier-wide balances in the stratigraphic system can be determined rigorously only by accurate spatially-distributed modeling or by gravimetric methods. Determinations based on field measurements must assume that the diachronous character of the summer surface can be neglected. The duration of the mass-balance year varies in the stratigraphic system.
That region of the Earth’s atmosphere between the troposphere and the mesosphere. It begins at an altitude of temperature minimum at approximately 13 km and defines a layer of increasing temperature u
p to about 50 km.
The second major layer of Earth's atmosphere, just above the troposphere and below the mesosphere, extending from about 20 km to 90 km above the Earth. It is characterized by little vertical increase
in temperature.
The layer of the atmosphere that extends fromthe troposphere to about 30 km, temperature increases with height. Thestratosphere contains the ozone layer.