Tiefseerinne

Verletzung der Isostasie

… trenches are characterized by large negative gravity anomalies. That is, there appears to be a mass deficiency beneath the trenches, and thus something must be holding the trenches down or else they would rise in order to restore isostatic equilibrium.

The most striking phenomenon associated with the trenches is a deficiency in gravity ... Measurements of gravity near trenches show pronounced departures from the expected values. These gravity anomalies are among the largest found on earth. It is clear that isostatic equilibrium does not exist near the trenches. The trench-producing forces must be acting ... to pull the crust under the trenches downward!

Flachwasserfossilien

It is perhaps especially remarkable that some material was recovered from the depths exceeding 7000 m in the trenches, even right down to the bottom of the Philippine Trench. … plant remnants, making them fossils [that are] rather surprising in the deep sea.

Materials [like fossils] which are usually supposed to be deposited only in shallow water have actually been found on the floor of some of the deep trenches.

Keine Deformation in horizontalen Sedimentschichten

… it would seem that the sediment sliding into the bottom of the trench should be folded into pronounced ridges and valleys. Yet virtually undeformed sediments have been mapped in trenches by David William Scholl and his colleagues at the U.S. Naval Electronics Laboratory Center. Furthermore, the enormous quantity of deep-ocean sediment that has presumably been swept up to the margins of trenches cannot be detected on sub-bottom profiling records.

Steilste Tiefseerinne