There are many ways to do this. The ice sheets are very remote places, so remote sensing methods are heavily relied upon. Satellite altimeters very precisely measure the distance between the satellite and the surface of the earth, and a temporal record gives changes in the elevation of the land, and therefore the ice sheet (with terms such as isostatic rebound accounted for). Passive microwave sensors are extremely good at detecting the onset of melt in the spring. They measure radiation emitted from the ice sheet in the microwave part of the spectrum, which is very sensitive to the transition from ice to water. This gives useful information about the spatial and temporal characteristics of ice melt, especially onset. Also, visible sensors can be used to some extent.
Much of the remaining work is done on the ground. Since melt water has to go somewhere, runoff is measured at the edge of glaciers at certain spots near the ice edge, and this provides a useful gauge of how melt is changing through time. Mass balance studies are also carried out on the ice sheet through snow pits and transects, for example, to see how the surface is changing in spot measurement. Radars are sometimes used on the ground to give an image of the ice sheet and can be compared to past data.
All of this data is often integrated into computer models that simulate, given these data and others such as heat fluxes and precipitation, how the ice sheet has been behaving and is likely to change in the future. Ground data serves as the validation for this.
Chat with our AI personalities
Glaciers are typically measured in meters or kilometers for length, and in square kilometers for area. Ice volume is often measured in cubic kilometers or cubic miles, and the mass of glaciers can be expressed in metric tons or gigatons. Temperature changes in glaciers are measured in degrees Celsius or Fahrenheit.
That depends what aspect of the glacier you want to measure. For example:
Units of measurement include meters for length, grams for mass, and liters for volume. Tools for measuring objects include rulers for length, scales for mass, and beakers for volume.
The SI unit of measurement scale is the International System of Units, which is the modern form of the metric system used in most countries around the world. It provides a consistent and standardized set of units for measuring physical quantities such as length, mass, and time.
The best unit of measurement to measure an alligator is in feet or meters, as these units are commonly used for measuring the length of large animals.
Common units for measuring volume in the metric system are milliliters (mL) and liters (L). The tool commonly used for measuring liquid volumes in the metric system is a graduated cylinder.
Watts, kilowatts, and megawatts are units of power measurement. Watts are small units, commonly used for measuring the power consumption of small electronic devices. Kilowatts are larger units, used for measuring household electricity consumption or the power output of a car engine. Megawatts are even larger units, typically used for measuring the power output of power plants or large industrial facilities.