E and 2 N and is bordered by Sulawesi to
the west, Halmahera to the east, the Sula Islands to the south,
and Mindanao and the Pacific to the north. The approximately
200,000 sq. km area of this sea are underlain by a fairly
complex series of troughs, basins and ridges that are usually
divided into three north-south zones. The westernmost zone
is the Sangir Trough connecting Davao Gulf in Mindanao with
the Gorontalo Gulf; the central zone a broad ridge outlined
by the 2000 m isobath which bears the Talaud and Miangas
islands in the north; and the eastern zone a series of depressions
and basins. This is also variously called the Maluku Sea.
The Molucca Sea is an important passageway for deep water
flowing from the Pacific Ocean through the Australasian Mediterranean
and on into the Indian Ocean. One branch of flow through the
Molucca is composed of deep flow from the Pacific through the
Sangir Trough and on into the Sulawesi Sea,
while another branch has flow entering via the Morotai Basin and
exiting via the Gorontalo Basin south of Sulawesia as well as
through the Lifamatola Strait into the
Banda and
Ceram Seas.
Surface salinities depart at most 0.3 from an annual average
of 34.0, although higher salinities have been recorded late in
the year in the north and southern extremities.
The surface salinities range from 28.3 C in June to
27.0 C in January.
The monsoon winds drive the surface circulation, changing slowly in direction from northeast to north-northwest during the southern summer and generally reversing direction during the winter months. As such a slow current flows southwestward along the eastern margin of the sea along with an opposite (northward) flowing current of similar strength in the western half in the winter months. The northward flow is maintained throughout the year except in the northern reaches where an east-southeast directed current occurs in the summer months. See Fairbridge (1966).
where g is gravitational acceleration, z the vertical
coordinate, T temperature and 
the specific heat at
constant pressure.
W.
S. The flow has been
estimated at about 6 Sv near 15 S increasing to 15 Sv
near 20 as the northward looping
East Madagascar Current
turns back towards the south and joins it.
This combined flow eventually becomes
the major part of the
Agulhas Current.