Further comment on the vertical-plate balance

Comment on "Intermittent plate tectonics?".

Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

Analysis of Laminar Film Condensation on a Vertical Plate

Response to Comment on “ Intermittent Plate Tectonics ? ”

The realization that Earth may have lost heat more slowly in the past than at present has motivated the search for mechanisms to reduce the efficiency of plate tectonics in the past. Several mechanisms have been proposed, such as the resistance to subduction of thick plates (1) produced by deeper melting at higher mantle temperatures (2). We (3) proposed an alternative mechanism, namely subduct...

A further comment on measurement of thyrotropin.

procedure and cannot be attributed to spectrophotometric insensitivity. (The major drawback of the Isomune-CK procedure is that it requires a sensitive spectrophotometer for the CK measurements.) Good precision is probably not mandatory for CK-MB quantitation when monitoring patients who have had acute myocardial infarcts, but we believe that it is essential when following patients who have und...

Horizontal versus vertical plate motions

We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr) than the vertical component (0.01–1 mm/yr) in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate 5 boundaries supports dominating tangential forces acting ...