explorers spend considerable time trying to understand and explain the environment in which we live and this type of ‘‘discovery’’ is an ongoing process that will
never end as long as human beings exist.
One of the most prestigious naturalists as well as oceanographers of the last
century was Alexander von Humboldt, founder of modern geography and meteorology. He was the person who drew the first isothermal map of the ocean. His
findings later helped to discover the existence of different density currents in the
oceans due to changes in water salinity and temperature. The present day Humboldt
Foundation was initiated with funding by the post World War II German government
to promote scientific exchange between the western nations’ scientific communities;
it was this same Humboldt Foundation that enabled me to continue my cooperative
programs with German institutions after I was obliged to retire at the age of 65 from
IFREMER (Institut Français de Recherche pour l’Exploitation de la Mer).
In 1910, a German meteorologist named Alfred Wegener and a US geologist
called Franck Taylor suggested that ‘‘continental drift’’ might be a possible
explanation for the shape and apparent fit of the European—African continents
with the North and South American continents. After World War II, long-range
exploration of the deep ocean floor was undertaken by the major US oceanographic centers.
It was in the 1960s that Harry Hess and Robert Dietz suggested that the sea
floor might be spreading from the area of the Mid-Oceanic Ridge axis. Henry
William Menard is another of these milestone scientists who has contributed to the
study of the Pacific islands and seamounts since the 1950s. At that time, we knew
very little about the growth and formation of submarine volcanoes and their
implications in forming oceanic islands.
Harry Hess hypothesized that continental drift is closely related to the presence
of convection currents in the mantle, which he claimed were the force for moving
the continents. The proof of continental drift came from the measurements of the
earth’s magnetic field (Vine and Matthews 1963) (see Chap. 2). The magnetic field
is what controls the compass needle, directing it to the north. However, it has been
established that the magnetism of our planet has jumped from north to south and
vice versa several times in the Earth’s past history. When volcanic rocks were
erupted on the Mid-Oceanic Ridge axis, they cooled rapidly and their iron-rich
minerals (magnetite) solidified in the direction of the magnetic field (the direction
of the compass needle) at the time of eruption. An observation of the changing
pattern of magnetic attraction from North to South and vice versa provides us with
a means for seeing the evolution of these erupted rocks over time and space.
In 1963, a Canadian geologist named Tuzo Wilson published an article in the
Canadian Journal of Physics where he suggested that the alignment of the
Hawaiian Island chain was the consequence of the lithospheric plate’s displacement over a fixed thermal source that he called a ‘‘plume’’. It was also Wilson
(1963, 1965), after looking at the Mid-Atlantic Ridge’s east-west trending fracture
zones, who suggested that the junction of the spreading ridge and the fracture
zones is the site of intense tectonic activity and called these structures ‘‘transform
faults’’. Indeed, these faults are the site of most of the world’s major earthquakes
Ocean Explorers and Pioneers in Oceanography
3
never end as long as human beings exist.
One of the most prestigious naturalists as well as oceanographers of the last
century was Alexander von Humboldt, founder of modern geography and meteorology. He was the person who drew the first isothermal map of the ocean. His
findings later helped to discover the existence of different density currents in the
oceans due to changes in water salinity and temperature. The present day Humboldt
Foundation was initiated with funding by the post World War II German government
to promote scientific exchange between the western nations’ scientific communities;
it was this same Humboldt Foundation that enabled me to continue my cooperative
programs with German institutions after I was obliged to retire at the age of 65 from
IFREMER (Institut Français de Recherche pour l’Exploitation de la Mer).
In 1910, a German meteorologist named Alfred Wegener and a US geologist
called Franck Taylor suggested that ‘‘continental drift’’ might be a possible
explanation for the shape and apparent fit of the European—African continents
with the North and South American continents. After World War II, long-range
exploration of the deep ocean floor was undertaken by the major US oceanographic centers.
It was in the 1960s that Harry Hess and Robert Dietz suggested that the sea
floor might be spreading from the area of the Mid-Oceanic Ridge axis. Henry
William Menard is another of these milestone scientists who has contributed to the
study of the Pacific islands and seamounts since the 1950s. At that time, we knew
very little about the growth and formation of submarine volcanoes and their
implications in forming oceanic islands.
Harry Hess hypothesized that continental drift is closely related to the presence
of convection currents in the mantle, which he claimed were the force for moving
the continents. The proof of continental drift came from the measurements of the
earth’s magnetic field (Vine and Matthews 1963) (see Chap. 2). The magnetic field
is what controls the compass needle, directing it to the north. However, it has been
established that the magnetism of our planet has jumped from north to south and
vice versa several times in the Earth’s past history. When volcanic rocks were
erupted on the Mid-Oceanic Ridge axis, they cooled rapidly and their iron-rich
minerals (magnetite) solidified in the direction of the magnetic field (the direction
of the compass needle) at the time of eruption. An observation of the changing
pattern of magnetic attraction from North to South and vice versa provides us with
a means for seeing the evolution of these erupted rocks over time and space.
In 1963, a Canadian geologist named Tuzo Wilson published an article in the
Canadian Journal of Physics where he suggested that the alignment of the
Hawaiian Island chain was the consequence of the lithospheric plate’s displacement over a fixed thermal source that he called a ‘‘plume’’. It was also Wilson
(1963, 1965), after looking at the Mid-Atlantic Ridge’s east-west trending fracture
zones, who suggested that the junction of the spreading ridge and the fracture
zones is the site of intense tectonic activity and called these structures ‘‘transform
faults’’. Indeed, these faults are the site of most of the world’s major earthquakes
Ocean Explorers and Pioneers in Oceanography
3