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23-540: Lake Timsah lies within a depression that spans the isthmus between the Red Sea and the Mediterranean Sea. The lowest points of the depression form shallow natural lakes, of which Timsah is one. The surface area of Lake Timsah covers 5.4 square miles. Most of the lake is marshy and depth rarely exceeds 3 feet (1 metre). It has been asserted that, in ancient times , Lake Timsah was the northern terminus of

46-412: A salt marsh is likely to develop. Wave refraction can occur at the end of a spit, carrying sediment around the end to form a hook or recurved spit. Refraction in multiple directions may create a complex spit. Waves that arrive in a direction other than obliquely along the spit will halt the growth of the spit, shorten it, or eventually destroy it entirely. The sediments that make up spits come from

69-558: A fresh water supply to the area. It was also proposed to construct a halfway port at this point along the canal. The Ismailia section of the Suez Canal , which connected Lake Manzala to Lake Timsah, was completed in November 1862. Construction of the segment was completed with forced labor , which expanded the workforce to 18,000 men. The trench measured 50 feet (15 m) wide by four to six feet deep and connected Lake Timsah to

92-406: A narrow stretch of sea between two landmasses that connects two larger bodies of water. Isthmus and land bridge are related terms, with isthmus having a broader meaning. A land bridge is an isthmus connecting Earth's major land masses. The term land bridge is usually used in biogeology to describe land connections that used to exist between continents at various times and were important for

115-422: A particularly advantageous shortcut for marine transport. For example: Spit (landform) A spit ( cognate with the word for a rotisserie bar) or sandspit is a deposition bar or beach landform off coasts or lake shores. It develops in places where re-entrance occurs, such as at a cove's headlands , by the process of longshore drift by longshore currents. The drift occurs due to waves meeting

138-419: A section of headland where the turn is greater than 30 degrees. The spit will continue out into the sea until water pressure (e.g. from a river) becomes too great to allow the sand to deposit. Vegetation may then start to grow on the spit, and the spit may become stable and often fertile. A spit may be considered a special form of a shoal . As spits grow, the water behind them is sheltered from wind and waves, and

161-436: A variety of sources including rivers and eroding bluffs, and changes there can have a major effect on spits and other coastal landforms. Activities such as logging and farming upstream can increase the sediment load of rivers, which may hurt the intertidal environments around spits by smothering delicate habitats. Roads or bulkheads built along bluffs can drastically reduce the volume of sediment eroded, so that not enough material

184-558: Is a brackish lake that experiences significant variations in salinity. Human engineering projects have impacted salinity, with resulting changes in the lake's biota. Decreases in salinity were noted as early as 1871 following Suez Canal construction, and subsequent enlargement of the channel from the Nile and other construction projects increased the inflow of fresh water to the lake. The El-Gamil outlet serves as Lake Timsah's principal source of salt water. Timsah's main source of fresh water

207-443: Is being pushed along to maintain the spit. If the supply of sediment is interrupted the sand at the neck (landward end) of the spit may be moved towards the head, eventually creating an island. If the supply is not interrupted, and the spit is not breached by the sea (or, if across an estuary, the river), the spit may become a bar , with both ends joined to land, and form a lagoon behind the bar. If an island lies offshore near where

230-488: The Mediterranean Sea . Work began south of Lake Timsah in 1862-1863 as expansion continued on the northern segment. Forced labor was used during canal construction from March 1862 until Ismail Pasha outlawed the practice in 1864. As a result of the canal, waters from Lake Manzaleh flowed into Lake Timsah. Expansion continued on the northern segment until 1867 and on the southern segment until 1876. Lake Timsah

253-547: The Red Sea . On March 4, 1863, the city of Ismailia , named in honor of the viceroy Ismail Pasha , arose on Lake Timsah's northern bank. Several beaches overlook the lake, including the Moslem Youth, Fayrouz, Melaha, Bahary , Taawen, and a few Suez Canal Authority beaches. Lake Timsah possibly first became a juncture for canal construction approximately 4,000 years ago during the Middle Kingdom of Egypt , and

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276-580: The Croatian island of Brač , is formed by Adriatic currents flowing east and west through the Hvar Channel , along the southern side of the island. The spit bends slightly west or east, changing its direction gradually, depending on the conditions of the tides and weather. Since prehistory humans have chosen certain spit formations as sites for human habitation. In some cases, these sites have been chosen for proximity to marine resource exploitation ;

299-448: The beach at an oblique angle, moving sediment down the beach in a zigzag pattern. This is complemented by longshore currents, which further transport sediment through the water alongside the beach. These currents are caused by the same waves that cause the drift. Where the direction of the shore inland re-enters , or changes direction, for example at a headland , the longshore current spreads out or dissipates. No longer able to carry

322-731: The coast changes direction, and the spit continues to grow until it connects the island to the mainland, it is called a tombolo . The end of a spit attached to land is called the proximal end, and the end jutting out into water is called the distal end. There is debate as to the longest spit in the world, with both the Arabat Spit in the Sea of Azov and the Younghusband Peninsula in South Australia approximately 110 kilometres (68 mi) long. Alternatively, with

345-464: The full load, much of the sediment is dropped. This is called deposition. This submerged bar of sediment allows longshore drift or littoral drift to continue to transport sediment in the direction the waves are breaking, forming an above-water spit. Without the complementary process of littoral drift, the bar would not build above the surface of the waves becoming a spit and would instead be leveled off underwater. Spits occur when longshore drift reaches

368-424: The lake is of economic importance to the city and its fishermen. Isthmus An isthmus ( / ˈ ɪ s m ə s , ˈ ɪ s θ m ə s / ; pl. : isthmuses or isthmi ) is a narrow piece of land connecting two larger areas across an expanse of water by which they are otherwise separated. A tombolo is an isthmus that consists of a spit or bar , and a strait is the sea counterpart of an isthmus,

391-405: The lake. Samples included tilapia , crabs, bivalves , clams and gastropods . The results showed that crabs contained "significantly higher concentrations of both total and carcinogenic PAHs than other species, while clams contained significantly lower levels of PAHs." In 2003, a number of groups attempted to relieve the lake of pollution. It was a significant event for the local community, since

414-703: The mainland. The Curonian Spit , off the coast of Lithuania and Kaliningrad Oblast of Russia , separates the Curonian Lagoon from the Baltic Sea ; it is 98 km long (61 mi). In a similar fashion, the Vistula Spit separates the Vistula Lagoon from the Gdańsk Bay off the coast of Poland . Zlatni Rat , a popular pebble beach jutting southward from the harbor town of Bol , on

437-796: The migration of people and various species of animals and plants, e.g. Beringia and Doggerland . An isthmus is a land connection between two bigger landmasses, while a peninsula is rather a land protrusion that is connected to a bigger landmass on one side only and surrounded by water on all other sides. Technically, an isthmus can have canals running from coast to coast (e.g. the Panama Canal ), and thus resemble two peninsulas; however, canals are artificial features distinguished from straits . The world's major isthmuses include: Of historic importance were: The cities of Auckland , Madison , Manila , and Seattle are located on isthmuses. Canals are often built across isthmuses, where they may be

460-671: The natural closing of the Roanoke inlet in 1811, Bodie Island in North Carolina may qualify as the longest, also measuring in at approximately 70 miles (110 km) to the peninsula's terminus at the Oregon Inlet . The longest spit in a freshwater body of water is Long Point, Ontario , which extends approximately 32 km (20 mi) into Lake Erie . Farewell Spit in New Zealand , at 32 km (20 mi), in

483-681: The north-west area of South Island , is believed to be caused by the strong prevailing winds and currents, bringing sand eroded from the Southern Alps of the South Island and depositing these into Golden Bay . A well-known spit in the UK is Spurn Point at the Humber ; it is approximately 4.8 km (3.0 mi) long. Another is Chesil Beach in the UK, which connects the Isle of Portland to

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506-574: Was annual Nile flooding until the Aswan High Dam interrupted these flows in 1966, although groundwater also accounts for much of the lake's freshwater supply. Lake Timsah experiences both stratification variations in salinity and seasonal surface variations in salinity, and in recent decades freshwater taxa have been overtaking brackish taxa. In 2002, a study was conducted to check the concentrations of polycyclic aromatic hydrocarbons (PAHs) in fish and shellfish species that locals consume from

529-463: Was expanded by Darius I . Suez Canal construction in the vicinity of Lake Timsah began in 1861 on the segment north of the lake. Initial preparations included the construction of sheds to house 10,000 workers, steam sawmills, and importation of large quantities of wheelbarrows and wooden planks. 3,000 laborers dug a channel ( Ismailia Canal ) from the Nile to Lake Timsah in 1861 and 1862, which brought

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