Identifier: thalassaessayond00wil (find matches)
Title: Thalassa; an essay on the depth, temperature, and currents of the ocean
Year: 1877 (1870s)
Authors: Wild, John James
Subjects: Ocean
Publisher: London, M. Ward & Co.
Contributing Library: Smithsonian Libraries
Digitizing Sponsor: Smithsonian Libraries

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
soundings taken in this basin, it appears thatan area of depression of over 1000 fathoms in depth extendssouthward from the strait between Spitzbergen and Greenland,in lat. 80° N., as far as the Fseroe Islands, and occupies thecentral part of the space between Greenland, Iceland, and Nor-way, gradually shelving up towards their shores. The volcanicisland of Jan Mayen rises from the bottom of this area to aheight of 6870 feet above the sea-level. The only deep-seacommunication between this basin and the Atlantic seems to beeffected by Denmark Strait, the unexplored space betweenIceland and Greenland. According to the temperature-sound-ings of the Voringen, a mass of cold water under 0° C.fills up this basin to within 403 fathoms of the sea-surface onthe Norwegian side, and to within 200 fathoms towards theeast coast of Iceland. An extension of this cold stratum wasdiscovered by H.M.S. Lightning and Porcupine in the500-fathom channel between the Faeroe Islands and the Britishplateau.
Text Appearing After Image:
CHAPTER II. TEMPERATURE OF THE OCEAN. Surface Temperature—Deep-Sea Temperature—The Miller-Casella Thermometer—Serial Soundings and Temperature Curves—Deductions from the Curve. Surface Temperature.—The temperature of the oceandepends mainly on three conditions—latitude, currents, and theseason of the year. Owing to the unequal exposure of thedifferent portions of the spherical surface of our planet to therays of the sun, the amount of solar heat received graduallydiminishes from a maximum between the tropics to a minimumin the polar regions. We find, in consequence, that the tem-perature of the surface-layer of the ocean decreases as weproceed from the Equator towards the Poles, slowly at firstbetween the tropics, more rapidly in the temperate zones, untilit falls to zero and even below zero before we reach the Arcticand Antarctic Circles (Plate 4). In the absence of any other disturbing cause, theIsotherms, or lines of equal temperature, would therefore forma system of li

Note About Images