Low tide in the context of "Tidal pool"

A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters. They also support terrestrial animals and provide coastal protection.

Salt marshes have historically been endangered by poorly implemented coastal management practices, with land reclaimed for human uses or polluted by upstream agriculture or other industrial coastal uses. Additionally, sea level rise caused by climate change is endangering other marshes, through erosion and submersion of otherwise tidal marshes. However, recent acknowledgment by both environmentalists and larger society for the importance of saltwater marshes for biodiversity, ecological productivity and other ecosystem services, such as carbon sequestration, have led to an increase in salt marsh restoration and management since the 1980s.

Tidal range is the difference in height between high tide and low tide. Tides are the rise and fall of sea levels caused by gravitational forces exerted by the Moon and Sun, by Earth's rotation and by centrifugal force caused by Earth's progression around the Earth-Moon barycenter. Tidal range depends on time and location.

Larger tidal range occur during spring tides (spring range), when the gravitational forces of both the Moon and Sun are aligned (at syzygy), reinforcing each other in the same direction (new moon) or in opposite directions (full moon). The largest annual tidal range can be expected around the time of the equinox if it coincides with a spring tide. Spring tides occur at the second and fourth (last) quarters of the lunar phases.

Southern dispersal, also known as the great coastal migration or rapid coastal settlement, was an early human migration along the southern coastal route, from the Arabian Peninsula via Persia and India to Southeast Asia and Oceania, with later descendants of those migrations eventually colonizing the rest of Eastern Eurasia and the Americas.

According to this thesis, the dispersal was possible thanks to the development of a multipurpose subsistence strategy, based on the collection of organisms, fish, crustaceans, molluscs, algae, which are part of the biotic communities of the intertidal zone, the transition ecosystem between land and sea between the upper limit of high tides and the lower limit of low tides, i.e. organisms left behind by the waters which retreat during ebb tide, and which people could harvest from the ground and reefs left unsubmerged or in shallow water at low tide. - In support of this hypothesis there are the remains found on an ancient Pleistocene reef, now emerged, near the locality of Abdur in Eritrea. Its rocks are the result of the compaction of marine debris about 125,000 years ago and contain fossil remains of a complex biotic community of the coast of the time: large colonies of corals, oyster shells, large clams and other bivalve molluscs, gastropods and echinoderms. A group of geologists and paleontologists found many blades and tools made of quartz, obsidian and other fine volcanic stone, mixed with the remains of shells. This would prove that over 100,000 years ago human populations of Homo sapiens exploited the intertidal zone for food purposes.

A polder (Dutch pronunciation: [ˈpɔldər] ) is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes. The three types of polder are:

1. Land reclaimed from a body of water, such as a lake or the seabed
2. Flood plains separated from the sea or river by a dike
3. Marshes separated from the surrounding water by a dike and subsequently drained; these are also known as koogs, especially in Germany

The ground level in drained marshes subsides over time. All polders will eventually be below the surrounding water level some or all of the time. Water enters the low-lying polder through infiltration and water pressure of groundwater, or rainfall, or transport of water by rivers and canals. This usually means that the polder has an excess of water, which is pumped out or drained by opening sluices at low tide. Care must be taken not to set the internal water level too low. Polder land made up of peat (former marshland) will sink in relation to its previous level, because of peat decomposing when exposed to oxygen from the air.

Kolbeinsey (Icelandic: [ˈkʰɔlˌpeinsˌeiː] ; also known as Kolbeinn's Isle, Seagull Rock, Mevenklint, Mevenklip, or Meeuw Steen) is a small Icelandic islet in the Greenland Sea located 105 kilometres (55 nautical miles) off the northern coast of Iceland, 74 km (40 nmi) north-northwest of the island of Grímsey. It is the northernmost point of Iceland and lies north of the Arctic Circle. The islet is named after Kolbeinn Sigmundarson, from Kolbeinsdalur in Skagafjörður, who according to Svarfdæla saga is said to have broken his ship there and died with his men.

A basalt landform, devoid of vegetation, Kolbeinsey is subject to rapid wave erosion and is expected to disappear in the near future. Erosion rate data from 1994 suggested that this would happen around 2020. In August 2020, English YouTuber Tom Scott published a video confirming the continued existence of the island, with two skerries still visible at low tide. As of April 2021, two small skerries remained visible at low tide.