No abstract

No abstract

No abstract

During experi ments on sf:d mcnt trnn.sport and real tanca to now with a un.Uorm o. 33 m.r.a sand, data w r t aken on Ute movement ot indh'i• dual rocks having lntermodiato diameters from about O. t to o. 5 foot. Th experiments were conducted in flumo z-toot wide by 60-foet long and for most runs, depth. WM held constant at o. 5 f'eet. The exp r:l menta showed t at rocks on U1e &and bed inov d down tren consistently only it the flow wa.s la the uppor regimci that la, only if 1be ed formi, were plmio boo, standii\i w :vcs , or snUdunes. The rocka moved at velocities th.at ere appro.dmately one • halt or tho averase ve-loc1ty Q.f the water. With all bed form3 in the low

No abstract

Conical mounds of ice have been observed to form in a few hours during violent winter storms along the edge of shore-fast ice near Dunkirk, New York. They occur in lines which parallel depth contours, and are evenly spaced in the manner of beach cusps. The height and spacing of mounds and number of rows vary from year to year depending on such factors as storm duration and intensity, and the position of the edge of the shore-fast ice at the beginning of the storm.The evenly sloping conical mounds have central channels which increase in width lakeward. The ice between the channels forms headlands above the lake surface. Spray-formed levees develop along the headlands and slope gently away from the lake margin. Lake marginal walls of ice are usually vertical.Spray, slush and ice blocks are ejected over the cone as each successive wave is focused by the converging channel walls. Ice blocks, interlayered with frozen slush and dirt, form bedding paralleling the sloping surface of cones, headlands and levees. These features are here termed “ice volcanoes” because their origin is in so many ways analogous to that of true volcanoes.

No abstract

No abstract