deformations are accompanied by tension (e I > 0) when σ I ̸ h > − 2P
*
̸ 3, and by
compression (e I < 0) when σ I ̸ h < − 2P
*
̸ 3.
Pure shear plastic deformations occur when the ice stresses divided by the ice
thickness σ I ̸ h and σ II ̸ h equal to the coordinates of point O s (Fig. 6). Slip lines
analysis shows that the angle between the slip lines is equal to 90° in the case of
pure shear deformations (e.g., [12]). In the case of plane motion the slip lines are
Fig. 5 Development of the circular faults in drift ice near the Alaska coast in 2016
Analytical Solutions Describing Zonal and Circular …
545
*
̸ 3, and by
compression (e I < 0) when σ I ̸ h < − 2P
*
̸ 3.
Pure shear plastic deformations occur when the ice stresses divided by the ice
thickness σ I ̸ h and σ II ̸ h equal to the coordinates of point O s (Fig. 6). Slip lines
analysis shows that the angle between the slip lines is equal to 90° in the case of
pure shear deformations (e.g., [12]). In the case of plane motion the slip lines are
Fig. 5 Development of the circular faults in drift ice near the Alaska coast in 2016
Analytical Solutions Describing Zonal and Circular …
545