Comparison of sounding surveys made 20 years apart have revealed that subsequent to thermal abrasion and retreat of coasts developed in ice‐rich Quaternary sediments in the Olenek‐Anabar section of the Laptev Sea coast, depths on the submarine nearshore slope continue to increase as a result of thermal abrasion, at rates which may attain 0.8–1.0 m over the period in question. On open sections of the Laptev Sea shelf sounding traverses have revealed the progressive development of thermokarst forms, particularly those resulting from the melting of ice wedges. Melting of smaller ice inclusions is also leading to a general lowering of the sea bed.