ICE Density Calculator
Our cryosphere & climate calculator computes ice density accurately. Enter measurements for results with formulas and error analysis.
Formula
rho = rho_pure x (1 - V_air)
Where rho_pure = 916.7 + 0.15 x |T| in kg/m3, V_air is air bubble fraction, with salinity and pressure corrections.
Frequently Asked Questions
What is the density of pure ice and how does temperature affect it?
Pure ice at 0 degrees Celsius has a density of approximately 916.7 kg/m3, about 8.4 percent less dense than liquid water. As temperature decreases, ice density increases slightly at roughly 0.15 kg/m3 per degree below freezing. At -30 degrees Celsius pure ice density reaches approximately 921.2 kg/m3. This anomalous property where solid is less dense than liquid is critical for aquatic ecosystems because ice floats and insulates the water below from extreme cold.
How do air bubbles affect ice density in glaciers?
Air bubbles trapped in glacier ice significantly reduce its bulk density below that of pure ice. Freshly fallen snow contains up to 90 percent air by volume giving densities as low as 50 to 100 kg/m3. As snow compacts into firn and glacier ice air content decreases. Typical glacier ice contains 2 to 10 percent air bubbles yielding densities between 830 and 900 kg/m3. At depths exceeding about 1000 meters enormous pressure compresses air bubbles into clathrate hydrates and ice density approaches its theoretical maximum.
What is the difference between snow, firn, and glacier ice density?
Snow, firn, and glacier ice represent a continuum of densification stages. Fresh snow has densities from 50 to 200 kg/m3 depending on crystal structure and wind. Settled snow and seasonal snowpack range from 200 to 500 kg/m3. Firn, multi-year compacted snow surviving at least one summer, has densities between 550 and 830 kg/m3. The transition from firn to glacier ice occurs at approximately 830 kg/m3 when interconnected air passages close to form isolated bubbles. Glacier ice ranges from 830 to 917 kg/m3.
How does salinity affect sea ice density?
Sea ice initially traps brine in pockets and channels making it denser than freshwater ice. Newly formed sea ice can have salinities of 10 to 15 parts per thousand and densities approaching 940 kg/m3. As sea ice ages gravity-driven brine drainage reduces salinity to 2 to 5 ppt in first-year ice and less than 1 ppt in multi-year ice. The brine volume depends on both salinity and temperature with warmer ice holding more liquid brine. Sea ice density ranges from approximately 900 to 940 kg/m3 depending on age and conditions.
Why does ice float and what fraction stays above water?
Ice floats because its density of approximately 917 kg/m3 is less than liquid water at 1000 kg/m3 and seawater at about 1025 kg/m3. By Archimedes principle the fraction submerged equals the ratio of ice to water density. In fresh water about 91.7 percent of an iceberg is submerged leaving 8.3 percent above the waterline. In seawater approximately 89.5 percent is submerged with 10.5 percent exposed. Actual icebergs with trapped air can float with somewhat more ice exposed above the surface.
How is ice density measured in the field?
Ice density is measured using several techniques. In the field ice cores are weighed and volume determined by measuring dimensions. Hydrostatic weighing provides more precise measurements. Gamma-ray attenuation logging measures density continuously along a core. For snow and firn a sampling tube of known volume is pushed into the snowpack. Modern techniques include micro-CT scanning revealing the three-dimensional structure of air inclusions within the ice sample.