DTM History

✦ On-land magnetic surveys accompanied the voyages of the "Carnegie" such as this one by sledge on Baffin Island, 1922. (Photo: Carnegie Archives)

✦ Map of postdoc countries of origin from November, 2017 DTM Newsletter. (courtesy Roberto Candanosa and Rick Carlson)

Carnegie's special approach -- the role of DTM

Department of Terrestrial Magnetism (DTM) Director Rick Carlson has a good write-up from his Nov. 2017 Newsletter of the role played by Carnegie staff in the scientific community. Read it here.

DTM Geochemistry and Cosmochemistry Heritage

(starts in 1951 -almost 15 years before plate tectonics!)

The idea was to use the understanding of physics of elements that undergo natural radioactive decay to date different minerals in rocks using three isotope systems in the same rock. At the time, four big problems (below) were given as a reason to undertake the quest of geochronology.

Exhibit at Carnegie Institution headquarters, December, 1952

✦ A poster detailing the first mineral age work done at the Carnegie Institution. (Photo: Carnegie Archives)

1. Age of Earth

“Age-determination studies have many objectives. Perhaps the foremost goal is to gather new data bearing on the long-standing and classic problem of the earth's age. The age of the earth is in ambiguo, and as science sharpens the tools for age determination, the earth's birthday is, year by year, being moved backward.”

2. Stratigraphy of Crystalline Rocks

“Stratigraphy of the great areas of crystalline rocks is another basic problem, where age determinations may serve to decipher the relationships, and where the classic methods of geology have failed to provide unambiguous answers.”

3. Origin and Growth of Continents

“The origin of continents by gradual growth about a nucleus — in the case of North America, the Canadian shield region — is a fascinating hypothesis....”

4. Ages of Intrusions

“Knowledge of the relative ages of intrusive rock formations is of vital importance in many mining areas of the world... Thus, age studies may well have economic as well as scientific value.”

—Founding of the DTM-GL Cooperative Investigation, “Age of Minerals” 1951 (from CIW Ybk ‘51)

✦ DTM scientist, Lloyd Berkner, inspecting multifrequency ionospheric equipment in 1937, Image No. I4466. (Photo: Carnegie Archives)

100 years of discovery: DTM 1904 - 2004

"Two years after the Carnegie Institution of Washington was formed in 1902, Louis Bauer, a scientist studying the Earth's magnetic field, was selected by the board of trustees to form the Department of Terrestrial Magnetism (DTM)."

Learn about DTM history here.

A Look Back at DTM

RV 'Carnegie' (1909-1929). "Her object: Sun and stars serve to shape a ship's course only when visible; however, as the Earth is a great magnet, the mariner's compass is directed unfailingly, be it night or day, cloudy or foggy. To reap the fullest benefit possible from this natural agency, the 'Carnegie' is mapping out the magnetic forces as they prevail over the oceans. Her mission is hence international." Quote attributed to Louis A Bauer. (photo: Carnegie Archives)