Mohammad Dibajnia

Cyclone Gonu: The Most Intense Tropical Cyclone on Record in the Arabian Sea

The Oman Sea and its neighboring countries’ (Iran and Oman) coastlines are subject to tropical cyclone influence on an infrequent basis; however, these cyclones can generate extremely large sea states. In general, cyclones generated in the Arabian Sea tend to travel either due west toward Oman or recurve north to strike Pakistan or India. They rarely enter the Oman Sea. Recently, in early June 2007, cyclone Gonu entered the Oman Sea and large waves were experienced along the Iranian and Omani coastlines. This cyclone had an unusual path, traveling much further west and north than the typical cyclone. Significant wave heights in excess of 4 m were measured at Chabahar located on the south coast of Iran bordering the Oman Sea.

Shoreline Response to Dike Failure at Grand Marais Harbor, Lake Superior, Michigan

This paper summarizes the main findings from the investigations that were conducted, including GIS comparison of historic air photos, an 18-year wave hindcast, longshore sediment transport calculations, and extensive 2DH numerical modeling of hydrodynamics and sediment transport at Grand Marais Harbor. A sediment budget is presented based on geomorphic assessment and numerical modeling results. Future shoreline positions are also predicted.

Geomorphic Features Shaped by Crossing Waves

Ridge-like shoal topography is well developed on the continental shelves of the Mid-Atlantic Bight and the northeastern Gulf of Mexico. In both cases, these linear sand ridges are oriented parallel to the predominant wave approach direction, suggesting common processes for their evolution and maintenance. Along the coasts of tropical islands surrounded by coral reefs, spur-like features are sometimes found. The spurs consist of coral rubble made available by the die-off or destruction of coral through natural processes or anthropogenic factors. The spur features emanate from rubble fields and are aligned parallel to the predominant direction of wave attack. These features, from disparate environmental settings, owe their maintenance and evolution to crossing wave patterns that form through refraction of waves up either side of the shoal or spur features. This paper presents examples of these geomorphic forms in both settings. Existing capabilities for simulating crossing wave processes are discussed.