BIGELOW: COAST WATER EXPLORATION OF 1913. 165 
The bottom temperature was higher south than north of Delaware 
Bay, and instead of being coldest over the mid-zone of the continental 
shelf, decreased from the shore seaward, with increasing depth. 
Temperature profiles. 'The lines were planned to afford three com- 
_ plete profiles across the continental shelf, one abreast of Montauk, 
one off Barnegat, and one opposite the mouth of Chesapeake Bay 
respectively, besides several incomplete ones in intermediate posi- 
tions, and a complete profile from the deep basin of the Gulf of 
_ Maine to the Gulf Stream via Georges and Nantucket Shoals. The 
latter (Fig. 9) shows that there was a marked temperature contrast 
between the waters on either side of the Shoals which form the 
southern boundary of the basin of the Gulf. On the north, the deep 
basin, below twenty-five fathoms, was filled with water of 42° or 
colder, with a rapid rise in the upper twenty fathoms to the surface 
temperature of 62°-63°. On the southern side, the coldest water was 
about 47°, at sixty fathoms, while the surface temperature was some 
6° warmer at the off shore end of the profile (Station 10061) than in 
the Gulf (68°). Over the Shoals in the centre of the profile there 
are local regions of complete vertical mixing by the tidal currents, 
as for instance on the southwest side of George’s Bank (Station 10059) 
where the temperature was practically uniform from surface to bot- 
tom (54.7°). On outer edge of the continental shelf the coldest water 
(47.3°) was not on the bottom, but at fifty fathoms, with warmer 
water (51.5°) below it. And as Gulf Stream water was to be expected 
only a few miles further off shore, it is fair to assume that this water 
colder than 50° indented the warmer ocean water like a tongue, as 
represented by the curve for 50°. The fact that there was no water 
on this line colder than 47° shows that the cold bottom water (45°) 
| west of Nantucket Shoals (Fig. 10) was not continuous with the still 
colder water of the Gulf of Maine. 
The next profile (Fig. 11), running from the neighborhood of 
New York to the 500 fathom curve in Lat. 39° 55’, shows the cold 
| water on the shelf at 20-40 fathoms, indenting into the warmer water 
| over the slope. The temperature was much higher, depth for depth, 
| outside the edge of the shelf, than over the latter, as is shown by the 
sharp seaward dip of all the curves. And at the shore end of the 
| profile the same was the case, the curves rising as the land is ap- 
proached, with equal temperatures about five fathoms nearer the 
surface at Station 10067 than at Station 10066. In the central part 
i the profile (Station 10065 to 10066) there was little horizontal 
change in temperature from east to west. 
