a9 
was close to that found by temperature-salinity measurements. The theory 
eave good agreement with the observed waves. At T-3, shallow-water sound 
propagation was studied and the results are now being analyzed. The data 
will show the features of shallow-water propagation on the Arctic Ocean 
continental shelf and rive information about the sediments. The results 
show that underwater sound trevels easily throughout the Arctic Ocean. 
Phenomena, natural or artificial which set up an acoustic disturbance should 
be readily detectable in all parts of the Arctic Ocean with relatively 
simple listening gear. 
Magnetic Studies 
At Alpha, two instruments were used to measure the earth's 
magnetic field. An Askania recording variometer was used to give a continous 
record of the relative value of the D, Z and H components. Records were 
made of photographic paper. A transit magnetometer was used to determine 
the absolute values of the D and H components at intervals. A summary of 
these D and H measurements on Alpha is included in the appendix to this 
report. These valves have some interest for the magnetic map of the Arctic 
to be used for navigation. The field is generally so disturbed, however, 
that continuous records must be made. 
A nuclear resonance magnetometer was used on Drifting Station 
Charlie. The instrument was read every 15 minutes for an absolute value 
of the total vector. The data shows significant magnetic anomalies over 
the flanks of the Chukchi Rise. This data has beén interpreted and will 
be published. Difficulties are found in interpretation due to the large 
disturbance effects. However, these can to a large extent be separated 
from geological effects by comparison with records mace at Pt. Barrow. 
