April 3] 1907 – December 4, 2006) was a Soviet Armenian scientist in the field of soil mechanics and engineering geology, one of the founders of the landslide studies, and the originator of the theories of the depth creep of slopes, the structural composition of post-ice-age clay and suspension pressure acting against filtration.

His father, Isaiah Zakharievich Ter-Stepanian, was a veterinary physician, whose ancestors moved from Ani, a city in Western Armenia (presently in Turkey), to Georgia in the 14th century.

As a result, during WWII, Ter-Stepanian was appointed a Chief of the Transcaucasian Research Party, a group entrusted with making projections about the landslide activation in strategically important military zones between the Caspian and the Black Seas.

Ter-Stepanian was the founder and chief editor of the trilingual (Armenian, Russian, English) scientific journal «Problems of Geomechanics», which was published between 1967 and 1988 and received wide international recognition.

For 20 years these essays appeared in the Köln based journal «Geotechnical Abstracts» of the German National Committee on Soil Mechanics and Foundation Engineering.

[32][33][34][35][36][37][38][39] As a prominent specialist in the field of Soil Mechanics and Engineering Geology, he was invited frequently to give lectures in Belgium, Bulgaria, Czechoslovakia, France, Hungary, Japan, Norway, Poland, Sweden, and other countries.

[41][42] In the late 1960s, Ter-Stepanian put up his opposition to the use of the Ararat Valley, a seismically active zone containing the only artesian water source in the region and located only 26 kilometers from Yerevan, the Republic's capital, as a building site for a new Nuclear power plant.

Ter-Stepanian is one of the founders of the study of landslides, and the originator of the theories of the depth creep of slopes, the structural composition of the post-ice-age clay and the Suspension Pressure Acting Against Filtration.

He was the first to establish the metastability of the structure of high-sensitivity late-glacial marine clays and to develop methods of studying them, which proved to be of a great economic importance.

Discovered first in Yerevan, this was subsequently confirmed in his studies of the mechanism of landslide burial in the High Pliocene Epoch in the ravine of the Hrazdan River and in the Ararat Valley.

In the field of Geomorphology, Ter-Stepanian isolated a new type of micro-relief in the form of accumulative ridges that are located along the entire length of slopes and related to the build-up of material along roads, balks and other obstacles.

He developed a piezometric method to carry out a field identification of the vertical total filtration pressure necessary to analyze the effective tension in the body of the landslide.

[63] In engineering geology, Ter-Stepanian studied the properties of soil foundations of the industrial, hydrotechnical and residential building sites on the territories of the former Soviet Union (Leningrad, Murmansk, Chita, Sochi, Yegorlyk, Armenia, Georgia, Volga River), and in Iran (Tabriz, Tehran, Isfahan, Mashhad).

The results are summarized in his monograph Geodetic Methods for Investigating the Dynamics of Landslides, which was published in two editions in Russian (Moscow, 1972 and 1979)[65] and in German (Leipzig, 1976).

[66] In the field of molecular physics, Ter-Stepanian researched the conditions of the equilibrium of capillary systems, isolating the mechanisms of capillary-balanced fluids that are similar in external appearance, but behave differently.

He has also discovered a unique landslide mechanism caused by capillary siphoning, by which water partly moves upward (to the surface) in the form of steam.

[67] In the field of soil rheology, Ter-Stepanian proposed a structural theory of the depth creep of slopes that was confirmed by nearly six years of extensive experimental research.

This idea was developed in his monograph entitled Beginning of the Quinary, or the Technogene: Engineering-geological Analysis (Yerevan, 1985), and was also presented at several congresses and in scientific papers.

In 1978 he completed a trilingual (English, Russian, Armenian) dictionary of geological and geotechnical terms and definitions, unique in its kind, which regrettably was not published.