How deep is an atoll lagoon?
How deep is an atoll lagoon?
atoll, coral reef enclosing a lagoon. Atolls consist of ribbons of reef that may not always be circular but whose broad configuration is a closed shape up to dozens of kilometres across, enclosing a lagoon that may be approximately 50 metres (160 feet) deep or more.
How deep must a lagoon be in a barrier reef?
A coral reef lagoon is that body of water that lies within an atoll (annular) reef or within a barrier reef. It is generally assumed that an appreciable depth of water is maintained within the lagoon, say 5-50 meters.
Are atoll lagoons deeper than coastal lagoons?
Atoll lagoons form when an island completely subsides beneath the water, leaving a ring of coral that continues to grow upwards. Coastal lagoons form along gently sloping coasts. They are generally shallower than atoll lagoons and tend to be separated from the ocean by an island, reef, or sand bank.
Is a lagoon deep or shallow?
A lagoon is a shallow body of water protected from a larger body of water (usually the ocean) by sandbars, barrier islands, or coral reefs. Lagoons are often called estuaries, sounds, bays, or even lakes. Lagoons sheltered by sandbars or barrier islands are called coastal lagoons.
How big can lagoons be?
Coral lagoon dimensions range from small atolls to those so wide that the coral reefs on the far side cannot be seen across the lagoon. Atoll widths range from about 2.5 to nearly 100 km (1.5 to nearly 62 miles), but the mean value is about 20 km (about 12 miles).
What requirements do the dinoflagellates Zooxanthellae have?
During the day, they provide their host with the organic carbon products of photosynthesis, sometimes providing up to 90% of their host’s energy needs for metabolism, growth and reproduction. In return, they receive nutrients, carbon dioxide, and an elevated position with access to sunshine.
What is the difference between a barrier reef and an atoll?
Atolls are usually circular or oval in shape, with an open lagoon in the center. Barrier reefs are similar to fringing reefs in that they also border a shoreline; however, instead of growing directly out from the shore, they are separated from land by an expanse of water.
How deep can lagoons be?
Lagoons are generally shallow compared to lakes. For instance, the depth of lagoons hardly exceeds 200 feet (for oceanic lagoons), and many of them are less than 65 feet deep (for coastal lagoons). The deepest lagoon is found in Comoro archipelago in Mayotte Island in the Indian Ocean and reaches a depth of 300 feet.
What’s the difference between an estuary and a lagoon?
The main difference between estuaries and lagoons lies in the flow dynamics of those water bodies. In estuaries the freshwater usually flows fast and forcefully towards the sea, whereas in lagoons the water is shallower and flows sluggishly.
What is a lagoon landform?
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into coastal lagoons and atoll lagoons. Lagoons are common coastal features around many parts of the world.
How deep is the Lagos Lagoon?
2-4 m deep
The Lagos Lagoon averages 2-4 m deep, but is 10 m deep in the entrance at the Commodore channel. Lagos Lagoon empties into the Atlantic Ocean via Lagos Harbour. The Lagos harbour or Commodore Channel is 0.5 km to 1 km wide and 10 km long.
What is the difference between a coastal lagoon and an atoll?
Atoll lagoon s are similar to coastal lagoons. Instead of being sheltered by sandbars or barrier islands, however, atoll lagoons are protected by coral reefs. Atoll lagoons are very common in the tropical waters of the South Pacific and Indian Oceans.
How many islands are there in the atoll of Atoll?
It is a small natural atoll 22 kilometres (14 miles) in length. It has 25 islands lying all around the boundary reef. One long barrier reef forms the western side of the atoll.
What are the characteristics of the atolls of the Maldives?
This atoll is oval in shape and small, its greatest length being 15.5 kilometres (9.6 miles). It is composed of 7 islands, 3 of which are inhabited. The inner lagoon has a depth of 17 to 20 fathoms (31 to 37 m); it has a sandy bottom mixed with mud and clay. Unlike the lagoons of most small atolls of the Maldives,…
What is the length of the atoll of Alifushi?
The islands stand on a detached reef of their own with very deep waters (no sounding) between this reef and the northern end of the main Atoll. The length of this atoll is 2 miles (3.2 kilometres) with a width of 1 mile (1.6 kilometres). Today, of the two islands, only Alifushi is inhabited.
