1900s

DTM ACHIEVEMENTS TIMELINE

1940s

First World Magnetic Survey begun

Improvements to magnetic compasses and anti-submarine devices during WWI

1910s Determination of the height of the ionosphere by radio sounding

1950s

Studies of the strong nuclear force by proton-proton scattering

Discovery of cosmic-ray decrease during solar storms (Forbush Effect)

Development of the proximity fuze in WWII

1920s

1960s

Discovery of radio emission from Jupiter

Development of the tools for geochronology

1930s

1970s

Measurement of galaxy rotation curves and the discovery of dark matter

1980s 1990s

Tracing 10Be from atmosphere to mantle and back in arc volcanoes, F Tera et al., 1986

Defining the 4-D structure of a continent

Discoveries of extrasolar planets

Discovery of fossil seismic anisotropy in the mantle

First detection of slow earthquakes

Delineation of the connection between subduction and mantle plumes

Research vessel Carnegie, 1909

DTM survey party in the Australian Outback, 1912

Magnetic survey expeditions on land and sea

The Best of the Decade

JP Ault with marine collimating-compass, 1919

G Breit and M Tuve with radio sounding equipment, ca. 1925 [courtesy Library of Congress]

O Dahl, C Brown, L Hafstad, and M Tuve with 2-meter Van de Graaff accelerator, 1935

Correlation of cosmic-ray and magnetic field intensity, SE Forbush, 1938

Schematic of radio frequency proximity fuze for anti-aircraft defense, 1943

RW Carlson, SJ Hardy, JS Dunlap

News coverage of the first detection of planetary radio emissions, 1955

E Bolton demonstrating agar gel method for hybridizing DNA, ca. 1962

Discovery of repeated DNA sequences in the genomes of higher organisms

U-Pb concordia diagram developed by G Wetherill for determining mineral ages, 1955

Image intensifiers for telescopes

WK Ford with Carnegie image tube spectrograph at Lowell Observatory, ca. 1965

Optical and radio rotational velocities of the Andromeda Galaxy, VC Rubin et al., 1970-1975

Return of oceanic crust to mantle during subduction, AW Hofmann and WM White, 1982

Seismic and geochronological results from the Kaapvaal Project in southern Africa, 2001

Discovery figure for the giant planet orbiting 47 UMa, RP Butler and GW Marcy, 1996

Shear-wave splitting reveals anisotropy in the mantle, PG Silver and WW Chan, 1988

First installation of a borehole strainmeter in Japan, 1971

Strain record of a slow earthquake sequence in Japan, IS Sacks, AT Linde, et al., 1981

No 10Be in mid-ocean ridge, oceanic island, and continental basalts

10Be in island arc volcanoes