the strips will begin to drift apart, because the larger floes will continue to move by inertia, while 

 the smaller floes will stop. 



With each change in the wind, the floes will regroup and new elongated strips will form 

 correspondingly. * 



The distance between the individual strips may vary greatly, from tens of miles to several 

 miles, depending on the quantity of ice and the size of the main floes which form on the leeward side 

 of each strip. 



If there is a coastline or immobile ice on the leeward side of the strips moving in this manner, 

 the individual strips, gradually moving on shore or onto the ice, will cause compression and subse- 

 quent hummock formation due to the loss of the inertia of each individual strip. Of course, the lines 

 of hummock formation will run parallel to the strips of ice. 



The wind formation of ice strips does not cease even in winter, except that in winter the indi- 

 vidual floes driven into strips quickly fuse together as a unit and drift as a new ice formation. When 

 the wind ceases, the strips do not break apart but remain large individual fields until they are 

 broken up by storms of sufficient force. In winter during stills the open spaces of water between the 

 strips becomes covered with young ice and subsequently in large ice fields strips of stronger (old) 

 and weaker (young) ice alternate. 



LITERATURE: 62, 77. 



142. Compressive and Dispersive Winds 



Let us assume (figure 144) that MN is a shoreline (or immobile ice). On drawing line ^C at 

 an angle a (drift angle of the ice in the given region) to line MN , we find that with any wind from 

 sector OA BC the wind movement of the ice will have a velocity component directed toward the shore 

 and therefore these winds will be compressive with respect to the shore, while winds from sector 

 OADC will be dispersive. Further, the greatest compressive forces will occur with a wind from B 

 toward and the greatest dispersive forces will occur with a wind from D toward . 



Going into further detail, we find that when the winds are from sector A OB , the drift angle of 

 the ice will be greater and with winds from sector BOC smaller than the angle of ice drift in the open 

 sea. Actually, with a wind from E toward , the drift speed of the floe (moving at a theoretical 

 angle of inclination to the wind direction) has two components: one perpendicular to the shoreline 

 and the other parallel to the shore from point M toward point N . Consequently the first component 

 will be damped by the resistance of the shoreline and the second will somewhat increase the total 

 drift angle. Naturally, when the wind is from sector COB, we will get the opposite picture and 

 individual cases, such as a possible zero drift angle or even an ice drift to the left of the direction 

 of the acting wind in the northern hemisphere. 



*In my opinion, the elongation of the open leads (razvodya) in a direction approximately perpen- 

 dicular to the direction of the wind explains the brilliant navigation in ice performed by sailing 

 vessels in the past. I confirmed this, during a voyage during which we rounded Franz Joseph Land 

 in 1932 on the motor sailing vessel Knipovich . 



390 



