BIGELOW: COAST WATER EXPLORATION OF 1913. 



227 



At Station 10065, over the 45 fathom curve, fifty miles south of Long 

 Island, the first reading was taken about five hours before high water 

 at Fire Island Inlet, the nearest shore station for which tidal data is 

 available. The surface current ran northwesterly for the first three 

 hours; and then veered to the north and northeast, in which direction 

 it flowed, till the end of the set. Of course the observation does not 

 show conclusively whether or not there was a dominant drift in any 

 direction, because it did not cover the 

 last half of the ebb; but it goes far 

 enough to show that the flood current 

 ran about northwest; the first half of 

 the ebb to the northeast, the strength 

 of the flood being .2-.6 knots, of the 

 ebb .4-.7 knots per hour (Fig. 64). 



The total drift for the part of the tide 

 covered by the set is about 1.8 knots 

 north. x\nd it seems hardly probable 

 that the last few hours of the ebb would 

 wholly nullify this, the general trend of 

 the coast in this region being such that 

 it is safe to assume that the last part of 

 the ebb flows about east, the first part 

 of the flood westerly. And even if the 

 late ebb ran southeast with a velocity 

 of .5 knots, there would still remain a 

 net northerly drift of nearly .5 knots. 

 It is therefore fair to conclude that 

 there was a slight dominant northerly 

 movement of the surface water over 

 this part of the continental shelf. 



The bottom current turned an hour 

 earlier than the surface current. Dur- 

 ing the last three hours of the flood the 

 flow on the bottom was toward the northwest, with a velocity dimin- 

 ishing from .4 knot to zero. It then veered to the south by east, and 

 south, running in that direction for three hours with the considerable 

 velocity of .35-.5 knot per hour. The total set showed a net move- 

 ment of water of about 1.4 knot toward the south-southwest; l:)ut it 

 is a c^uestion whether there was any dominant flow on the bottom, 

 for if the current veered to the southeast and east during the last of 

 the ebb, with a northwest current throughout the flood, as is not 

 unlikely, the net drift would be neutralized. 



Fig. 64. — Surface current , 



and bottom current at 



Station 10065; hourly from 9 

 A.M. to 3 P.M., July 12. The 

 distance between dots (.) shows 

 the drift for each hour; 2.25 

 cm. = 1 sea mile. The compass 

 arrows are trxie and magnetic. 



