"Peering beneath an Erupting Volcano on the Bottom of the Ocean"

With Guest ScientistDr. Suzanne Carbotte

Originally presented 10 Mar 2012

Exploration of the Sea Floor Began with “HMS Challenger”

• First organized oceanographic expedition

• Circumnavigated the globe between 1872-76

• Used weighted piano wire to “sound” the sea floor

• Discovered the Mid-Ocean Ridge System

http://life.bio.sunysb.edu/marinebio/ch_01.jpg

In the 1920s, echo-sounding provided technology for real-time images

SO undNA vigationandR anging• First developed in the

1920s• Rapid developments

during “Age of Electronics”

• USS Stewart made soundings across Atlantic

http://oceanexplorer.noaa.gov/history/electronic/media/18_ussstewart.html

In 1923, Francis Shepard went on his Daddy’s yacht, and invented Marine Geology

• Born to a wealthy New England family (Shepard Shipping Co.) in 1897

• Early research focused on the Rockies and other mountains

• Daddy offered his yacht for cruise off NE coast, which opened his eyes to geological problems hidden beneath the waves

• “Father of Submarine Geology”

During World War II, vast amounts of echo-sounding records were collected by

ships crossing the oceans• Originally used for

ASW (anti-submarine warfare)

• US Navy provided many to Lamont after the war for research

http://www.oicinc.com/images/DiagramEchoSounding.jpg

Beginning in the 1950s, Marie Tharp, Bruce Heezen, and their grad students created

physiographic maps of the sea floors

http://www.earthinstitute.columbia.edu/news/images/TharpMapLarge.jpg

Acoustic and seismic research

• has contributed more to understanding Earth’s physical history, natural hazard potential, and climate systems than perhaps all other scientific technology combined

• gives scientists the ability to map the ocean floor, a tool that revolutionized earth sciences 50 years ago with the discovery that continents break apart and tectonic plates shift

Acoustic and seismic research

• revealed the globe-encircling volcanic mid-ocean ridge system, earthquake-producing boundaries of crustal plates, drowned shorelines, and submarine landslide deposits.

Acoustic and seismic research

• opaqueness of seawater to light or radio waves makes it difficult to efficiently study with either optical methods (cameras, etc), or with radar or microwave radiation (such as used in satellites).

• Sound, however, travels freely through the oceans and can be used to measure topography and to map geology, ocean temperatures, and currents

Seismic Imaging

http://www.ldeo.columbia.edu/tamam/approach-imaging-sediments-and-deformation

East Pacific Rise

• Part of Mid-Ocean Ridge System

• Extends northward from Pacific-Antarctic Ridge

• Includes some of the fastest-spreading portions of sea floor

http://www.nature.com/nature/journal/v393/n6686/images/393625aa.eps.2.gif

http://tos.org/oceanography/archive/25-1_fornari2.pdf

“ALVIN”

• Research submersible designed by Allyn Vine for WHOI

• “Mother ship” Atlantis• Can descend deeper than

14,500 ft (4800 m)• Among many accomplishments

was pivotal role in ProjectFAMOUS (1974) http://oceanexplorer.noaa.gov/technology/subs/alvin/alvin.html

http://www.britannica.com/blogs/wp-content/uploads/2009/11/alvin.jpg

Hydrothermal Vents

• Discovered by Alvin in1978 on EPR

• Now known in many other locations

http://www.seasky.org/deep-sea/assets/images/black-smoker-se39.jpg

http://www.photolib.noaa.gov/htmls/nur04512.htm

RIDGE 2000• Multidisciplinary science

research program focused on integrated geological and biological studies of the Earth-encircling oceanic spreading center system

• Integrated Studies focus on geology & biology of spreading center system

• Time Critical Studies enhance detection of volcanoes and other transient events, allow rapid-responsehttp://www.ridge2000.org/

LDEO East Pacific Rise Research

• 3D MultiChannel Seismic Survey of the magmatic-hydrothermal system East Pacific Rise 9°50‘N

• Analysis of 9°50'N East Pacific Rise Seismicity: Insight into Hydrothermal and Magmatic Processes

http://www.ldeo.columbia.edu/3DMCS

http://www.ldeo.columbia.edu/research/office-of-marine-operations

Lamont pioneered many seismic exploration technologies, first with the Vema and continuing now with the Marcus G. Langseth

http://www.ldeo.columbia.edu/research/marine-geology-geophysics

Collecting seismic data as the Marcus G Langseth crosses the ocean