24
Gilberto Rodriguez
b
d
Fig. 2.4. Lake Maracaibo: a bottom contour; b surface currents; c oxygen isopleths at 20 m depth;
d primary productivity (g C m'day-l) (a, b, c: data from Parra Pardi 1979; d: data from Battelle Memorial Institute 1973)
sphere, including Lake Maracaibo. They attributed this pattern to the drag of the wind
blowing across the bodies of water. In Lake Maracaibo this circulation is initiated by the
position of the Catatumbo Delta and facilitated by the quasi-circular shape of the lake.
The velocity of the surface current can reach up to 0.50 m S-l. Its direction does
not change with depth, but its velocity is reduced. Towards the center of the lake the
velocity decreases rapidly in the first 3 m and from 20 m up to the bottom. In the southern part of the lake this vertical decrement is very regular (Redfield et al. 1955).
There is a fluctuation of the force of the surface current in the northern part of the
lake, which follows a semidiurnal cycle with a short inversion of the current direction
during a part of the tidal cycle. Along the southern coast the velocity is not reduced
but there is a short inversion of the direction which does not exactly match the tidal
cycle. The behaviour of these currents, in phase with those in the Strait follows
Gilberto Rodriguez
b
d
Fig. 2.4. Lake Maracaibo: a bottom contour; b surface currents; c oxygen isopleths at 20 m depth;
d primary productivity (g C m'day-l) (a, b, c: data from Parra Pardi 1979; d: data from Battelle Memorial Institute 1973)
sphere, including Lake Maracaibo. They attributed this pattern to the drag of the wind
blowing across the bodies of water. In Lake Maracaibo this circulation is initiated by the
position of the Catatumbo Delta and facilitated by the quasi-circular shape of the lake.
The velocity of the surface current can reach up to 0.50 m S-l. Its direction does
not change with depth, but its velocity is reduced. Towards the center of the lake the
velocity decreases rapidly in the first 3 m and from 20 m up to the bottom. In the southern part of the lake this vertical decrement is very regular (Redfield et al. 1955).
There is a fluctuation of the force of the surface current in the northern part of the
lake, which follows a semidiurnal cycle with a short inversion of the current direction
during a part of the tidal cycle. Along the southern coast the velocity is not reduced
but there is a short inversion of the direction which does not exactly match the tidal
cycle. The behaviour of these currents, in phase with those in the Strait follows