THE 



GEOLOGICAL MAGAZINE. 



NEW SERIES. DECADE IV. VOL. 



No. III.— MARCH, 1896. 



ORIGINAL ARTICLES. 



I. — The Merjelen Lake (Aletsch Glacier). 



By C. S. Du Riche Prellek, M.A., Ph.D., M.T.E.E., F.G.S., F.C.S. 



(PLATE VI.) 



THE Merjelen or Maerjalen Lake, situated at an altitude of 2367 

 metres (7750 ft.) above sea-level at the western flank of the 

 Great Aletsch glacier, belongs to the class of glacier lakes which 

 are found in depressions or valleys barred by glaciers whose direction 

 of flow is more or less at right angles to the same. Like the 

 majority of glacier lakes, it has the shape of an irregular triangle, 

 the length being about L5 kilometre (nearly a mile), its greatest 



7K.TH 



width 0*5 kilometre (550 yards), and its mean depth 28 metres 

 (92 ft.). Hence its superficial area amounts to 375,000 square 

 metres (438,000 square yards), and its volume at high-water level 

 to about 10 million cubic metres or tons. 



As is shown in the section reduced by the writer from the 

 Swiss Contour Map, the lake is shut in by the Eggishorn to 

 the south and by Strahlhorn to the north, wbile at its western or 

 broader end it is barred by an ice- wall 500 metres (550 yards) in 



DECADE IV. VOL. III. NO. III. 7 



