3.3 The Major West Pacific Warm Pool Currents
43
Pool in global atmospheric circulation and its capacity for amplifying or moderating ENSO events. Because “radiative forcing changes have a large influence on
ENSO dynamics, affecting global maritime distribution and oceanographic conditions”, understanding the oceanographic history of the WPWP and its influence on
ENSO variability has an important place in modern research as a means of predicting the role of the WPWP under conditions of global warming [6]. Understanding
the complex roles of the WPWP and the history of changes within the Warm Pool,
however, is also relevant for understanding the past. They reflect global climate
change, affect ENSO amplitude and so are relevant to our specific concern: understanding the role of the WPWP’s outflowing currents in shaping prehistoric oceanic
exploration, trading and migration over millennia in both the Indian and Pacific
Oceans.
3.3 The Major West Pacific Warm Pool Currents
Warm water from the WPWP is dispersed into the Pacific and Indian Oceans through
four major currents flowing out from the Pool. The Kuro Shio Current drives northwards through Micronesia to Japan and then flows east to Hawaii and the southern
coast of California. Turning south along the west coast of America it then turns
west above the equator and, as the North Equatorial Current, travels back across
the Pacific to the Spice Islands. A second major current flowing out of the WPWP
forms a clockwise loop in the northern Indian Ocean, flowing west as the Equatorial
Current to the east coast of Africa, turning north and flowing up this coast and
then returning as the Indian Counter Current to Timor. A third major WPWP current, the East Australian Current, flows south parallel to the east coast of Australia
before reversing direction in response to the landmass of New Zealand and then
flowing north along the west coasts of the South Island and of the North Island.
This current would have drawn canoes to a landing on the west coast of the South
Island (the landing place recorded in traditional accounts of the earliest voyages to
New Zealand). The fourth major current, the West Australian or Leeuwin Current,
after the last Ice Age flood, reversed its direction to flow southwards along the west
coast of Western Australia.
The first three of these four currents have major significance for a Spice Islandbased Polynesian prehistory. The high SSTs of the WPWP offered Spice Island
mariners some protection against hypothermia over short distances in the Ice Age. In
the second half of the Holocene, adopting the strategy of following powerful warm
currents flowing out from the WPWP gave Spice Island mariners some protection
against hypothermia in ocean waters far outside the Pool and further reduced the
risk of hypothermia by ensuring fast passages over long distances. As we shall see,
this protection supported the Spice Islanders’ eventual development of transoceanic
exploration, trading and migration.
In this chapter we argue that the history of Spice Island maritime trading exploration and colonization is linked to the geological and oceanographic history of the
43
Pool in global atmospheric circulation and its capacity for amplifying or moderating ENSO events. Because “radiative forcing changes have a large influence on
ENSO dynamics, affecting global maritime distribution and oceanographic conditions”, understanding the oceanographic history of the WPWP and its influence on
ENSO variability has an important place in modern research as a means of predicting the role of the WPWP under conditions of global warming [6]. Understanding
the complex roles of the WPWP and the history of changes within the Warm Pool,
however, is also relevant for understanding the past. They reflect global climate
change, affect ENSO amplitude and so are relevant to our specific concern: understanding the role of the WPWP’s outflowing currents in shaping prehistoric oceanic
exploration, trading and migration over millennia in both the Indian and Pacific
Oceans.
3.3 The Major West Pacific Warm Pool Currents
Warm water from the WPWP is dispersed into the Pacific and Indian Oceans through
four major currents flowing out from the Pool. The Kuro Shio Current drives northwards through Micronesia to Japan and then flows east to Hawaii and the southern
coast of California. Turning south along the west coast of America it then turns
west above the equator and, as the North Equatorial Current, travels back across
the Pacific to the Spice Islands. A second major current flowing out of the WPWP
forms a clockwise loop in the northern Indian Ocean, flowing west as the Equatorial
Current to the east coast of Africa, turning north and flowing up this coast and
then returning as the Indian Counter Current to Timor. A third major WPWP current, the East Australian Current, flows south parallel to the east coast of Australia
before reversing direction in response to the landmass of New Zealand and then
flowing north along the west coasts of the South Island and of the North Island.
This current would have drawn canoes to a landing on the west coast of the South
Island (the landing place recorded in traditional accounts of the earliest voyages to
New Zealand). The fourth major current, the West Australian or Leeuwin Current,
after the last Ice Age flood, reversed its direction to flow southwards along the west
coast of Western Australia.
The first three of these four currents have major significance for a Spice Islandbased Polynesian prehistory. The high SSTs of the WPWP offered Spice Island
mariners some protection against hypothermia over short distances in the Ice Age. In
the second half of the Holocene, adopting the strategy of following powerful warm
currents flowing out from the WPWP gave Spice Island mariners some protection
against hypothermia in ocean waters far outside the Pool and further reduced the
risk of hypothermia by ensuring fast passages over long distances. As we shall see,
this protection supported the Spice Islanders’ eventual development of transoceanic
exploration, trading and migration.
In this chapter we argue that the history of Spice Island maritime trading exploration and colonization is linked to the geological and oceanographic history of the