Measurements of Sea-Ice Stresses Near Grounded Obstacles

Stresses were measured in multiyear sea ice near a grounded floe island. Compressive stresses as high as 250 psi (1.72 MPa) were observed, in the form of impulses. A second installation in annual sea ice near a grounded pressure ridge showed tensile stress of 100 psi (0.69 MPa), followed by crack formation. These stresses were localized to a range of the order of 100 m. Localized compressive stresses in multiyear ice near grounded offshore structures may exceed 250 psi (1.72 MPa), and impulsive loading should be expected.