56
The Suez Canal
lasts 9-10 months and the summer flow 2-3 months. It is hard to reach any
conclusions from these data.
Miller and Munns (1974) make some very interesting calculations bearing on
the evaporative losses in the Bitter Lake during the months of July and August.
Although these calculations are based on a combination of old information obtained by these authors from Morcos with measurements made by the "Atlantis
11" in July 1963, the results are interesting. According to these, the Bitter Lake
received an excess of seawater inflow from the Red Sea of 432,734 m 3 jday. Taking
into account the incoming salinity value of the sea water and salinity existing in
the Bitter Lake (on the assumption that all the concentration resulted from evaporation) the authors reached a figure of 771,000 m 3 jday to be evaporated. To
make up for the differences which resulted, "contributions from the Mediterranean ofNile indrafts" are necessary in these summer months.
Many authors, among them Morcos, saw in the summer southward current
also a result of the piling up of Nile waters at Port Said, following the opening of
the Nile dams which used to occur in these months. After the final closure of the
Aswan Dam, Morcos (1967a) mentions that in September 1966 a weak northward current appeared in the Canal.
According to the "Red Sea and Gulf of Aden Pilot" (1955) there is no sufficient
evidence to prove that the southward current in the northern Canal was caused
by the seasonal rise of the Nile. EI Sabh (1968) indeed considers that Morcos' data
from 1966 represents a meteorologically abnormal situation and that no fundamental change in the current patterns occurred after the cessation of the Nile flow
in early 1966. Oren (1970) agrees that the Nile rise did not playa crucial role.
Even though the surface current flows southward during the late summer, both
Wüst (1935) and Gohar (1954) speak of a bottom outflow of heavy saline Bitter
Lake water on the bottom of the northern Canal even in the summer months.
Temperatures. There are few relevant data on water-temperature for the Suez
Canal. Nonetheless, temperature has often been mentioned in speculations on the
animal migration through the Canal.
Without supplying the appropriate data, Wüst (1934) asserted that temperature differences in the Canal system were very small. Fox (1926) and later W.
Steinitz (1929) speak of the high water temperatures of the Canal as a barrier to
animal migration. Other authors see the Canal merely as a gradient of decreasing
temperatures from the Red Sea to the Mediterranean.
The temperature ranges as they appear below result from few measurements:
those of the "Pola" in October 1895 and May 1896 (Luksch, 1898); Wimpenny
(1930) between 1928 and 1929; Gruvel (1936) in April 1933 and between August
and October 1934; EI Sabh (1969) in 1966; the temperatures measured by "Atlantis 11" and "Chain" in July 1963, February 1965 and October and November 1966
(Miller and Munns, 1974); finally the temperatures measured in 1967 and 1969 by
the Hebrew University team (Por and Ferber, 1972).
The maximum temperatures found are around 30° C: in September 1934
30° C at Ismailia; 30S C at Kabrit in July 1963; 29.92° C in the Bitter Lake in
September 1966; 29.60° C in July 1928 in Lake Timsah; 29.70° C in June 1967 in
the Bitter Lake. The high temperature period in the Canal system comprises,
therefore, the months June-September.
The Suez Canal
lasts 9-10 months and the summer flow 2-3 months. It is hard to reach any
conclusions from these data.
Miller and Munns (1974) make some very interesting calculations bearing on
the evaporative losses in the Bitter Lake during the months of July and August.
Although these calculations are based on a combination of old information obtained by these authors from Morcos with measurements made by the "Atlantis
11" in July 1963, the results are interesting. According to these, the Bitter Lake
received an excess of seawater inflow from the Red Sea of 432,734 m 3 jday. Taking
into account the incoming salinity value of the sea water and salinity existing in
the Bitter Lake (on the assumption that all the concentration resulted from evaporation) the authors reached a figure of 771,000 m 3 jday to be evaporated. To
make up for the differences which resulted, "contributions from the Mediterranean ofNile indrafts" are necessary in these summer months.
Many authors, among them Morcos, saw in the summer southward current
also a result of the piling up of Nile waters at Port Said, following the opening of
the Nile dams which used to occur in these months. After the final closure of the
Aswan Dam, Morcos (1967a) mentions that in September 1966 a weak northward current appeared in the Canal.
According to the "Red Sea and Gulf of Aden Pilot" (1955) there is no sufficient
evidence to prove that the southward current in the northern Canal was caused
by the seasonal rise of the Nile. EI Sabh (1968) indeed considers that Morcos' data
from 1966 represents a meteorologically abnormal situation and that no fundamental change in the current patterns occurred after the cessation of the Nile flow
in early 1966. Oren (1970) agrees that the Nile rise did not playa crucial role.
Even though the surface current flows southward during the late summer, both
Wüst (1935) and Gohar (1954) speak of a bottom outflow of heavy saline Bitter
Lake water on the bottom of the northern Canal even in the summer months.
Temperatures. There are few relevant data on water-temperature for the Suez
Canal. Nonetheless, temperature has often been mentioned in speculations on the
animal migration through the Canal.
Without supplying the appropriate data, Wüst (1934) asserted that temperature differences in the Canal system were very small. Fox (1926) and later W.
Steinitz (1929) speak of the high water temperatures of the Canal as a barrier to
animal migration. Other authors see the Canal merely as a gradient of decreasing
temperatures from the Red Sea to the Mediterranean.
The temperature ranges as they appear below result from few measurements:
those of the "Pola" in October 1895 and May 1896 (Luksch, 1898); Wimpenny
(1930) between 1928 and 1929; Gruvel (1936) in April 1933 and between August
and October 1934; EI Sabh (1969) in 1966; the temperatures measured by "Atlantis 11" and "Chain" in July 1963, February 1965 and October and November 1966
(Miller and Munns, 1974); finally the temperatures measured in 1967 and 1969 by
the Hebrew University team (Por and Ferber, 1972).
The maximum temperatures found are around 30° C: in September 1934
30° C at Ismailia; 30S C at Kabrit in July 1963; 29.92° C in the Bitter Lake in
September 1966; 29.60° C in July 1928 in Lake Timsah; 29.70° C in June 1967 in
the Bitter Lake. The high temperature period in the Canal system comprises,
therefore, the months June-September.