76 



PRINCIPLES OF STRATIGRAPHY 



eastern coast of Asia, the most northerly of such, likewise produce 

 these results, the weather being cold, clear and dry in winter, and 

 cool, cloudy and damp in summer. 



3. Interior Continental Climates. In the interior of continents 

 climatic changes are for the most part very pronounced. The an- 

 nual temperature ranges become greater with increased distance 

 from the shore, the coldest and warmest months in the northern 

 hemisphere being January and July, respectively. There being less 

 cloudiness over the land, the diurnal changes are greater than over 

 the sea. These ranges are well shown by a comparison of the Janu- 

 ary and July temperatures of coast and inland stations in low and 

 high latitudes. 



January 

 temperature 



F. 



July-August 

 temperature 



Low Latitudes: 



Bagdad, Asia Minor (continental) 



Funchal, Island of Madeira (ma- 

 rine) 



High Latitudes: 



Nertschinsk, E. Siberia (conti- 

 nental) 



Valentia, southwest Ireland (ma- 

 rine) 



+ 11.5° 



+53° 



4-60° 



—25.6° 



+45-5' 



+34° 



+22.5° 



-1-22° 



+16° 



+93° 



+ 72.5° 



+ 71-6° 

 -f6o.8° 



The mean range of many observations in widely distributed sta- 

 tions is 8.2° C. for marine, and 39.0° C. for continental climates. 

 (Hann-40: 142.) 



The relative humidity of continental interiors is of course much 

 lower than that over the sea or on the coast, but even in arid regions 

 it may reach 20 per cent, or 30 per cent. The rainfall decreases in 

 amount and frequency as we proceed inland, except where local 

 topographic features act as modifiers. The winds average lower 

 in velocity, and calms are more freqtient over the land than over 

 the sea. Continental winds are sometimes so well developed as to 

 become monsoons. 



