Beach profile changes - east coast of Lake Michigan, 1970-72 / by R.A. Davis, W.G. Fingleton, and P.C. Pritchett.

Abstract

Approved for public release; distribution unlimited. 17. DISTRIBUTION STATEMENT (ol the abstract entered In Block 20, If dUterent trom Report) 18. SUPPLEMENTARY NOTES 19. KEY WORDS (Continue i side if necessary and identify by block number) Lake Michigan Bluff erosion Beach changes Lake levels Shore erosion 20. ABSTRACT (Continu reverse side if neceawary and identify by block i The primary result of this field study of beach changes on the eastern shore of Lake Michigan concerned the movement of the bluff or the edge of the terrace marking the landward boundary of the beach. Data collected every 4 weeks from August 1970 to August 1972 indicated recession or no change at each of 17 profile sites on a 250-mile segment of the east coast of Lake Michigan. During this period, lake levels were rising from a mean of 578.9 feet above mean water level (MWL) in 1970 to 579.7 feet MWL in 1972. The DD ,^5 EDITION OF I NOV 65 IS OBSOLETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE(TWl«n Datm Entend) 20. Abstract. (Continued) maximum bluff erosion at any one site between monthly surveys was 20 feet at profile 4 in June 1972. Variables affecting the rate of movement of the bluff include lake level, composition of the bluff or terrace, orientation and straightness of shoreline, wave climate, manmade structures, and possibly longshore bars. There was a lack of correlation between bluff erosion at nearby stations, but each site varied seasonally with maximum erosion occurring in late fall when storm occurrence is also high. Shore ice protected the beaches in winter; erosion resumed in spring at a reduced level. Beach width from the base of the bluff to the water level at the time of the survey also varied seasonally, with beaches narrow in early summer when lake level is at a maximum and wider in late fall when lake level is at a lower level. The study beaches were mostly well-sorted sand (mean grain size between 0.330 to 0.189 millimeter or 1.60 and 2.40 phi units) with some gravel and heavy mineral concentrations.Û NCLASSIFIED SECURITY CLASSIFICATION OF THIS P AGE(T»7ion Dafa Bnlerad) PREFACE This report is published to provide coastal engineers with reliable profile and sediment data collected during a 2-year study of beach changes along a 250-mile segment of the eastern shore of Lake Michigan. The work was carried out under the coastal processes program of the U.S. Army Coastal Engineering Research Center (CERC). The data for the report were collected under CERC Contract No.

Thermodynamics of diffusive DM/DE systems

“…The variation of the total entropy S + S de during universe expansion depends on the scale factor a and will be discussed in Sec.6. In the generalized second law of thermodynamics [17,18,19,35,36] the entropy of the apparent horizon plays an important role contributing to the entropy increase [37] and compensating the entropy decrease during expansion of other components. However, in models of this section the entropy of the dark sector is increasing (see Sec.6).…”

“…In this paper, in a particular model, we study the temperature of the components and an evolution of their entropy. In sec.6 we discuss also the generalized second law of thermo-dynamics [17,18,19] (taking into account the entropy of the horizon). The entropy of the horizon is the dominating contribution to the universe entropy [11,12] , but it does not change the conclusions about the entropy increase in the models of diffusive interactions.…”

The Coastal Morphology and Sedimentology of Cape Hatt Peninsula

“…They are usually less than 1 m in diameter and 30 cm in depth. The formation of kettles has often been attributed to the melting of ice cakes or boulders buried in beach sediments during freeze-up in both arctic (Owens and McCann, 1970;Greene, 1970;Short and Wiseman, 1974;Nichols, 1961) and non-arctic cold environments (Davis, 1973;Dionne and Laverdiere, 1972). However, kettles are not necessarily spring thaw phenomena; they can also be produced during the summer open water season by the grounding and rocking motion of floes, growlers and cakes followed by melting in situ or refloating (Taylor, 1981;Short, 1976;Dionne, 1969Dionne, ,1971.…”