|
A logarithmic spiral beach is a type of beach which develops in the direction under which it is sheltered by a headland, in an area called the shadow zone. It is characterized as a logarithmic spiral because if you look at it in plan view or aerially, it represents the same shape that is created from the logarithmic spiral relation. These beaches are also commonly referred to as ‘half heart’ or ‘crenulate’ shaped bays, or ‘headland bays’. == Logarithmic spiral relation == The logarithmic spiral can be determined using the equation (written in polar coordinates): r = eθcotα where: θ = the angle of rotation, is located between two lines drawn from the origin to any two points on the spiral. r = the ratio of the lengths between two lines that extend out from the origin. The two lines are given as RO and R. So r also equals the ratio R/RO. α = the angle between any line R from the origin and the line tangent to the spiral which is at the point where line R intersects the spiral. α is a constant for any given logarithmic spiral. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Logarithmic spiral beaches」の詳細全文を読む スポンサード リンク
|