Vol.. 6, 1920 
GEOPHYSICS: H. S. WASHINGTON 
583 
of California, constitute an exemplar of intensive oceanographical investi- 
gation. By systematically and repeatedly tabulating and mapping 
standardized values of the temperature, salinity, density, currents, and 
gas content of the water of the Pacific Ocean, serially observed at ascer- 
tained intervals of depth from the surface to the bottom in fixed loca- 
tions, the variations of these physical elements, with time and locality, in 
their distribution in the depths, have been revealed to an important 
extent within the confines of the oceanic tract in the region of the seat 
of the Institution, stretching from San Diego to Point Concepcion and em- 
bracing an area of more than 10,000 square miles. 
It is the present purpose of the Section of Physical Oceanography to 
foster the labors of these agencies and the similar ones which are con- 
tributed by the Navy and the Coast Survey and to seek opportunities to 
supplement them and link their operations, as far as may be, into coordi- 
nation with the operations of the oceanographers of Japan, of Australia 
and New Zealand, of the North Sea International Council of Exploration, 
and the Mediterranean Sea International Council of Exploration. And, 
through the formation of committees, to provide that consideration shall 
be given to the problems of evaporation and heat transference and the 
interrelations between oceanography and meteorology, to the problems of 
dynamic oceanography including the variations of mean sea-level and the 
tides and their manifestations in the depths as well as the surface, to the 
investigation of the chemical and physical properties of the waters includ- 
ing the penetration of light, to the investigation of the origin and distri- 
bution of bottom deposits, to the problem of ascertaining the conforma- 
tion and topography of the basins, and to the ways and means of 
advancement in the domain of physical oceanography. 
THE PROBLEMS OF VOLCANOLOGY 
By Henry S. Washington 
INTRODUCTION 
Of the various sciences represented in the American Geophysical Union 
that of volcanology is perhaps the most complex and has probably most 
points of contact with the other geophysical sciences. This complexity 
and variety in the problems presented by the study of volcanoes arises, in 
part, from the fact that they are, as has been well said, "natural labora- 
tories." Also the distribution and many of the activities of volcanoes 
are closely connected with some of the physical, as well as the chemical 
forces that are involved in the formation and in the present condition of 
the earth. 
In presenting some of the main problems of volcanology, we may be- 
gin with those that are essentially and more purely volcanological, and 
