Tables 690 and 691 



TABLE 690. — Temperature Variation over Earth's Surface (Harm) 



557 



TABLE 691. — Temperature Variation with Depth (Land and Ocean) 



Table illustrates temperature changes underground at moderate depths due to surface warming (read from plot 

 for Tiflis, Lehrbuch der Meteorologie, Hann and Siiring. 191 5). Below 20-30 m (nearer the surface in tropics) there 

 is no annual variation. Increase downwards at greater depths, 0.03 ±'C per m (i° per 35 m) I. c. At Pittsburgh, 

 1524 m, 49.4°, .0294 per m; Oberschlesien, 2003 m. 70°, .0294 per m; or W. Virginia, 2200 m, 70 , .034° per m (Van 

 Orstrand). Mean value outflow heat from earth's center, 0.00000172 g-cal/cm 2 /sec. or 54 g-cal/cmVyear (39 Laby). 

 Open ocean temperatures: Greatest mean annual range (Schott) 40° N, 4.2° C; 30° S, 5.1°; but 10° N, only 2.2 ; 

 50° S, 2. 9 . Mean surface temp, whole ocean (Krummel) 17. 4 ; all depths, 3.9 . Below 1 km nearly isothermal with 

 depth. In tropics, surface 28°; at 183 m. n°, 80% all water less than 4.4°. Deep-sea (bottom) temps, range — 0.5° to 

 + 2.6°. Soundings in S. Atlantic: o km, 18.9°; .25 km, 15°; .5 km, 8.3 ; 1 km, 3.3 ; 3 km, 1.7 ; 4.5 km, o.6°. 



Smithsonian Tables. 



