Spring tide in the context of "Antipodal point"

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.

Coastal flooding occurs when dry and low-lying land is submerged (flooded) by seawater. The range of a coastal flooding is a result of the elevation of floodwater that penetrates the inland which is controlled by the topography of the coastal land exposed to flooding. The seawater can flood the land via several different paths: direct flooding, overtopping or breaching of a barrier. Coastal flooding is largely a natural event. Due to the effects of climate change (e.g. sea level rise and an increase in extreme weather events) and an increase in the population living in coastal areas, the damage caused by coastal flood events has intensified and more people are being affected.

Coastal areas are sometimes flooded by unusually high tides, such as spring tides, especially when compounded by high winds and storm surges. This was the cause of the North Sea flood of 1953 which flooded large swathes of the Netherlands and the East coast of England.

The Naruto whirlpools (鳴門の渦潮, Naruto no Uzushio) are tidal whirlpools in the Naruto Strait, a channel between Naruto in Tokushima and Awaji Island in Hyōgo, Japan. The strait between Naruto and Awaji island has a width of about 1.3 km (0.81 miles). The strait is one of the connections between the Pacific Ocean and the Inland Sea, a body of water separating Honshū and Shikoku, two of the main islands of Japan. The tide moves large amounts of water into and out of the Inland Sea twice a day. With a range of up to 1.7 m (5.6 ft), the tide creates a difference in the water level of up to 1.5 m (4 ft 11 in) between the Inland Sea and the Pacific. Due to the narrowness of the strait, the water rushes through the Naruto channel at a speed of about 13–15 km/h (8–9 mph) four times a day, twice flowing in and twice flowing out. During a spring tide, the speed of the water may reach 20 km/h (12 mph), creating vortices up to 20 m (66 ft) in diameter.

The current in the strait is the fastest in Japan and the fourth fastest in the world after the Saltstraumen outside Bodø in Norway, which reaches speeds of 37 km/h (23 mph), the Moskenstraumen off the Lofoten islands in Norway (the original maelstrom) reaching 27.8 km/h (17.3 mph); and the Old Sow whirlpool in New Brunswick, Canada with up to 27.6 km/h (17.1 mph).

The Gulf of Gabes (or Cabès, Cabes, Gaps; Arabic: خليج قابس, romanized: ḫalīǧ Qābis), also known as Lesser Syrtis (from Ancient Greek: Μικρά Σύρτις, romanized: Mikrá Sýrtis; Latin: Syrtis Minor), contrasting with the Greater Syrtis in Libya, is a gulf on Tunisia's east coast in the Mediterranean Sea, off North Africa. The gulf roughly spans the coast from Sfax to Djerba. At the head of the gulf is the city of Gabès (Ghannouche) where the tides have a large range of up to 2.1 m at spring tides. Both Gabès and Sfax are major ports on the gulf, supporting sponge and tuna fisheries, with Gabès being the economic and administrative center.

The North Sea flood of 1953, also known as the Big Flood or East Coast Flood (in England) or as the Flood Disaster (Dutch: Watersnoodramp), was a flood caused by a heavy storm surge in the North Sea that struck low-lying coastal areas of the Netherlands, Belgium, and the United Kingdom. More than 2,000 people were killed on land and hundreds more at sea. It was the worst natural disaster of the 20th century in the United Kingdom and the worst in the Netherlands since the Middle Ages.

The storm and flooding occurred during the night of Saturday, 31 January to the morning of 1 February 1953. A combination of a high spring tide and a severe European windstorm caused a storm tide of the North Sea. Most sea defences facing the surge were overwhelmed, resulting in extensive flooding. The combination of wind, high tide, and low pressure caused the sea to flood land up to 5.6 metres (18 ft 4 in) above mean sea level.