38 THE FLOOR OF THE OCEAN 



greatest — more than 275 meters or about 900 feet — where the 

 ice had been thickest and heaviest. 



The recoil of the earth's crust is still going on. The map of 

 Figure 18 gives approximately the present rates of uplift as 



FIGURE l8. MAP SHOWING APPROXIMATELY THE LINES OF EQUAL RATES OF 

 CURRENT UPHEAVAL IN FENNOSCANDIA. THE NUMBERS REPRESENT MILLI- 

 METERS PER ANNUM. AFTER A. PENCK. 



determined by tide-gages; here the numbers on the different 

 contour-lines indicate in millimeters the annual amount of 

 upheaval along the respective lines. According to the map the 

 rate of vertical uplift at the Bothnian center is now about one 

 meter per century. If the movement continues long enough, 



