298
D. H. CUSHING
large number of radiocarbon measurements were made during the
International Indian Ocean Expedition, which have been reported by
Kabanova (1968) ; her Fig. 1 shows that there are observations in all
areas. Figure 14 shows the distribution in the north-east monsoon
(above) and in the south-west monsoon (below). During the north-east
monsoon there is high production off Sangor Island, the Orissa coast
and between Burma and the Andaman 1sla.nds in the Bay of Bengal,
and off W. Ceylon. It is surprising that there are points of production
on the Orissa coast during the north-east monsoon; Lafond (1957)
pointed out that there was upwelling on this coast during the southwest monsoon. In the southern winter, there is high production off the
southern islands of Indonesia and on the north-west coast of Australia
and off north-east Madagascar. Kabanova also examined the surface
radiocarbon measurements and found that intense production occurred
off the Malabar coast of India, which extended seawards for a considerable distance. Figure 14 shows the distribution of radiocarbon
measurements in the photic layer during the south-west monsoon.
Prominent is the intense production in the Somali Current and off
southern Arabia, again extending to seaward for a considerable distance. The production off north-west Australia remains fairly high, as
does that south of Java. An unexpected result is the rich band of high
production off the eastern coasts of South Africa, in the Agulhas Current,
which is a western boundary current, where upwelling does not take
place : Burchall (1968a, b) has shown that the zone of high production
lies inshore of the main axis of the Agulhas Current. However, there is
moderately high production up to 500 miles offshore (Mitchell-Innes,
1967 ; Thorrington-Smith, 1969). Another interesting point is that the
undercurrent at the equator does not appear at all in the radiocarbon
distributions, as it does in those in the Pacific (Fig. 13). In the Indonesian area including the South China Sea, there are observations from
the “ Galathea ” Expedition and a number of others, summarized by
Angot (1961). The Japan Science Council, National Committee for
IIOE (1966) has summarized some observations in detail off Java and
off north-west Australia which have been used here. There are also
observations in each of the Flores, Banda and Arafura Seas, off Vietnam
and in the Gulf of Thailand which are also reported by Kabanova. The
most important areas in the h d i a n Ocean and in the Indonesian region,
including the South China Sea, are those off Somalia and southern
Arabia, which are comparable in intensity to any upwelling area in the
world. But they are somewhat smaller and endure for rather shorter
seasons than the four major upwelling areas. The Orissa coast has only
been explored lightly during the south-west monsoon and probably is
D. H. CUSHING
large number of radiocarbon measurements were made during the
International Indian Ocean Expedition, which have been reported by
Kabanova (1968) ; her Fig. 1 shows that there are observations in all
areas. Figure 14 shows the distribution in the north-east monsoon
(above) and in the south-west monsoon (below). During the north-east
monsoon there is high production off Sangor Island, the Orissa coast
and between Burma and the Andaman 1sla.nds in the Bay of Bengal,
and off W. Ceylon. It is surprising that there are points of production
on the Orissa coast during the north-east monsoon; Lafond (1957)
pointed out that there was upwelling on this coast during the southwest monsoon. In the southern winter, there is high production off the
southern islands of Indonesia and on the north-west coast of Australia
and off north-east Madagascar. Kabanova also examined the surface
radiocarbon measurements and found that intense production occurred
off the Malabar coast of India, which extended seawards for a considerable distance. Figure 14 shows the distribution of radiocarbon
measurements in the photic layer during the south-west monsoon.
Prominent is the intense production in the Somali Current and off
southern Arabia, again extending to seaward for a considerable distance. The production off north-west Australia remains fairly high, as
does that south of Java. An unexpected result is the rich band of high
production off the eastern coasts of South Africa, in the Agulhas Current,
which is a western boundary current, where upwelling does not take
place : Burchall (1968a, b) has shown that the zone of high production
lies inshore of the main axis of the Agulhas Current. However, there is
moderately high production up to 500 miles offshore (Mitchell-Innes,
1967 ; Thorrington-Smith, 1969). Another interesting point is that the
undercurrent at the equator does not appear at all in the radiocarbon
distributions, as it does in those in the Pacific (Fig. 13). In the Indonesian area including the South China Sea, there are observations from
the “ Galathea ” Expedition and a number of others, summarized by
Angot (1961). The Japan Science Council, National Committee for
IIOE (1966) has summarized some observations in detail off Java and
off north-west Australia which have been used here. There are also
observations in each of the Flores, Banda and Arafura Seas, off Vietnam
and in the Gulf of Thailand which are also reported by Kabanova. The
most important areas in the h d i a n Ocean and in the Indonesian region,
including the South China Sea, are those off Somalia and southern
Arabia, which are comparable in intensity to any upwelling area in the
world. But they are somewhat smaller and endure for rather shorter
seasons than the four major upwelling areas. The Orissa coast has only
been explored lightly during the south-west monsoon and probably is