How Long Will It Take for This Giant Ice Cube to Melt?

Update: At Inverse‘s request, Fenty ran the cube’s dimensions through his ice climate model. He estimates that in full exposure to sunlight, the cube will survive around 30 to 40 days. But depending on how much of its surface benefits from wind and shade, that figure could run three or even four times longer. The cube’s lifespan could also be affected by how dirty it becomes - dark ice, because it absorbs more solar radiation, melts at a faster rate than does clean ice. “It’s humbling that even sophisticated ice models cannot accurately predict the lifetime of this cube. Ice melting is a highly nonlinear process,” Fenty wrote. “Unless the cube survives through December, which is entirely possible, the cube will rarely get cold enough for ambient water vapor to freeze onto its surface.”

On Friday, an extremely large (possibly the world’s largest?) ice cube was installed in downtown Seattle. It is art. That is, until our global warming-spiked atmosphere reduces the giant ice cube to what will presumably be a large and poignant puddle, whereupon it will just be melted art.

The installation, titled Ice Cube, weighs 10 tons and measures 80 inches on each side (it’s actually made up of a bunch of smaller cubes joined together). It’s the work of architecture firm Olson Kundig, which doesn’t actually know how long it will take for the thing to melt. That means people have resorted to guessing how long it will take.

Melting is a three-level process. First, we have sublimation, where the water that’s frozen in the ice matrix evaporates. Sublimation plays a big part in climate change-related glacial melting at the poles, which still don’t really get warm enough to transfer much heat from the sun.

“It’ll take a lot of time for all the heat to come out of that core,” said Dr. Ian Fenty of NASA’s Jet Propulsion Laboratory. “Seattle has a very moist environment, so there’s less sublimation than [in other parts of the world]. Water from the atmosphere could even be freezing back onto the surface of the cube.”

Then there’s warming of the ice via radiation. This could mean either short-wave solar radiation (from, you know, the sun) or long-wave infrared radiation (from ambient sources).

And finally, heat flux, or the exchange of kinetic energy from air molecules. This is what a standard mercury thermometer registers. The level of energy held by molecules in the air changes when it hits the trapped water molecules, subsequently liberating some of those molecules from a solid form to a liquid one.

Olson Kundig, meanwhile, offers this more poetic take:

“ICE CUBE, a temporary installation designed by Olson Kundig, showcases the stages of the natural water cycle as the ice shifts from opaque to translucent. As the 10-ton ice cube evaporates and melts, it offers a cool respite to visitors and scatters ambient sunlight and colors throughout the park. The pure form of the cube will gradually erode in the summer sun, marking the passage of time as its waters slowly return to the sea.”

Either way, this makes watching paint dry an almost exciting activity.