Frost Heave

February 24, 2015


Photographer: Rebecca Roush
Summary AuthorRebecca Roush

Frost heave refers to a soil condition resulting when sufficient water in soil freezes, causing the soil to heave upward as the freezing water expands. In order for frost heave to occur, specific environmental factors have to be in play: the rate of freezing, an abundant water supply and soils fine grained enough to allow water to be held above the water table.

Various natural and human-made landscapes can be detrimentally affected by frost heave. Plants and trees that are not well established can literally be pushed out of the ground, their demise guaranteed by exposed roots. Road beds can heave, crack, and deform. Rail beds can be warped, making train travel impossible. Buildings can be lifted and damaged, requiring repair. For almost 100 years this phenomenon has been studied by scientists and engineers, in part to aid better construction of roads and railways.

The photograph above was taken at Sound Transit’s Issaquah Transit Center in Issaquah, Washington. Frost heave can be seen around a landscaped tree. Though it doesn't appear to be severe enough to have injured the tree, it may have damaged the surrounding shrubs. Photo taken on January 2, 2015.

Photo details: Camera Model: Canon PowerShot SD1100 IS; Focal Length: 18.6mm; Aperture: ƒ/4.9; Exposure Time: 0.033 s (1/30); ISO equiv: 200.