46
Martin V. ANGEL
Fig. 3.1. The redistribution of the continental land masses as a result of continental drift at various intervals following the beginning of
the fragmentation of the super-continent Pangea about 200 million years B.P. The arrows indicate the likely patterns of surface currents
generated by the winds and influenced by the Earth’s rotational effects. Redrawn from Parish and Curtis (1982).
296×10
6 km
3 . Its maximum depth of 9560 m is in
the Puerto Rico Trench. Otherwise its margins are
tectonically passive, so that any slope failures result in
extensive transport of turbidite
2 deposits far out across
the abyssal plains.
The catastrophic events triggering the flows of water
carrying the very high loads of suspended material
that contribute most, if not all, of the material in
each turbidite layer are highly intermittent, and are
often set off by seismic events. On the other hand, the
intervening layers between the turbidites are deposited
over several millennia as a result of the slow continuous
deposition of pelagic material. Hence there is a
sharp contrast between the mineralogical content and
character of the two types of deposit.
The Atlantic is the only ocean that has a deepwater connection with the Arctic Ocean. Warm Atlantic
water flows north-eastwards into the Norwegian Sea
and feeds the Spitsbergen Current; this outflow from
the Atlantic has a major influence on the hydrography
and ecology of the Arctic. These warm surface outflows
from the Atlantic are balanced by cold inflows spilling
over the ridges that lie between Greenland, Iceland, the
Færøes and Scotland, and at the surface from the East
Greenland Current, which carries southwards towards
Nova Scotia icebergs spawned from the Greenland
glaciers, such as the one which sank the Titanic.
Atlantic hydrography is also greatly affected by the
inflows from the Mediterranean and Caribbean (see
Chapter 9). It also receives inputs from the Indian
2 See Glossary, p. 477.
Martin V. ANGEL
Fig. 3.1. The redistribution of the continental land masses as a result of continental drift at various intervals following the beginning of
the fragmentation of the super-continent Pangea about 200 million years B.P. The arrows indicate the likely patterns of surface currents
generated by the winds and influenced by the Earth’s rotational effects. Redrawn from Parish and Curtis (1982).
296×10
6 km
3 . Its maximum depth of 9560 m is in
the Puerto Rico Trench. Otherwise its margins are
tectonically passive, so that any slope failures result in
extensive transport of turbidite
2 deposits far out across
the abyssal plains.
The catastrophic events triggering the flows of water
carrying the very high loads of suspended material
that contribute most, if not all, of the material in
each turbidite layer are highly intermittent, and are
often set off by seismic events. On the other hand, the
intervening layers between the turbidites are deposited
over several millennia as a result of the slow continuous
deposition of pelagic material. Hence there is a
sharp contrast between the mineralogical content and
character of the two types of deposit.
The Atlantic is the only ocean that has a deepwater connection with the Arctic Ocean. Warm Atlantic
water flows north-eastwards into the Norwegian Sea
and feeds the Spitsbergen Current; this outflow from
the Atlantic has a major influence on the hydrography
and ecology of the Arctic. These warm surface outflows
from the Atlantic are balanced by cold inflows spilling
over the ridges that lie between Greenland, Iceland, the
Færøes and Scotland, and at the surface from the East
Greenland Current, which carries southwards towards
Nova Scotia icebergs spawned from the Greenland
glaciers, such as the one which sank the Titanic.
Atlantic hydrography is also greatly affected by the
inflows from the Mediterranean and Caribbean (see
Chapter 9). It also receives inputs from the Indian
2 See Glossary, p. 477.