81-416: Tidelands are the territory between the tide line of sea coasts , and lands lying under the sea beyond the low-water limit of the tide, considered within the territorial waters of a nation. The United States Constitution does not specify whether ownership of these lands rests with the federal government or with individual states. Originally little commercial value was attached to tidelands, so ownership
162-677: A day were similar, but at springs the tides rose 7 feet (2.1 m) in the morning but 9 feet (2.7 m) in the evening. Pierre-Simon Laplace formulated a system of partial differential equations relating the ocean's horizontal flow to its surface height, the first major dynamic theory for water tides. The Laplace tidal equations are still in use today. William Thomson, 1st Baron Kelvin , rewrote Laplace's equations in terms of vorticity which allowed for solutions describing tidally driven coastally trapped waves, known as Kelvin waves . Others including Kelvin and Henri Poincaré further developed Laplace's theory. Based on these developments and
243-445: A day—is a third regular category. Tides vary on timescales ranging from hours to years due to a number of factors, which determine the lunitidal interval . To make accurate records, tide gauges at fixed stations measure water level over time. Gauges ignore variations caused by waves with periods shorter than minutes. These data are compared to the reference (or datum) level usually called mean sea level . While tides are usually
324-512: A few days after (or before) new and full moon and are highest around the equinoxes, though Pliny noted many relationships now regarded as fanciful. In his Geography , Strabo described tides in the Persian Gulf having their greatest range when the moon was furthest from the plane of the Equator. All this despite the relatively small amplitude of Mediterranean basin tides. (The strong currents through
405-558: A great extent by its long established tourism industry but also by its position as a gateway to the Caribbean and Latin America . As of 2024, Texas and Florida are the second and third most populous states in the nation, respectively. Other areas of the Gulf Coast have benefited less, though economic development fueled by tourism has greatly increased property values along the coast, and is now
486-512: A smooth sphere covered by a sufficiently deep ocean under the tidal force of a single deforming body is a prolate spheroid (essentially a three-dimensional oval) with major axis directed toward the deforming body. Maclaurin was the first to write about the Earth's rotational effects on motion. Euler realized that the tidal force's horizontal component (more than the vertical) drives the tide. In 1744 Jean le Rond d'Alembert studied tidal equations for
567-512: A state could establish the existence of a boundary in judicial proceedings. The Outer Continental Shelf Lands Act gave the United States paramount rights from the point where state ownership leaves off to the point where international waters begin. The 1953 acts did not end all controversy, however. The Submerged Lands Act, in particular, was so badly drawn up that state taxes and leasing fees had to be put in escrow , pending final resolution of
648-798: A state in the United States in 1845 stipulated that its tidelands remained the territory of Texas . This has been an issue for oil and natural gas leases and federally funded development that affects such tidelands. For other states that were formerly independent, such as the Thirteen Colonies , there was no explicit retention of state sovereignty and the federal government had long asserted its own sovereignty over their tidelands. The value of tidelands increased when it became known that vast oil and natural gas deposits lay within their limits and that modern technology made retrieval of these minerals commercially profitable. The first offshore oil well in
729-514: A system of pulleys to add together six harmonic time functions. It was "programmed" by resetting gears and chains to adjust phasing and amplitudes. Similar machines were used until the 1960s. The first known sea-level record of an entire spring–neap cycle was made in 1831 on the Navy Dock in the Thames Estuary . Many large ports had automatic tide gauge stations by 1850. John Lubbock was one of
810-455: Is a useful concept. Tidal stage is also measured in degrees, with 360° per tidal cycle. Lines of constant tidal phase are called cotidal lines , which are analogous to contour lines of constant altitude on topographical maps , and when plotted form a cotidal map or cotidal chart . High water is reached simultaneously along the cotidal lines extending from the coast out into the ocean, and cotidal lines (and hence tidal phases) advance along
891-422: Is at once cotidal with high and low waters, which is satisfied by zero tidal motion. (The rare exception occurs when the tide encircles an island, as it does around New Zealand, Iceland and Madagascar .) Tidal motion generally lessens moving away from continental coasts, so that crossing the cotidal lines are contours of constant amplitude (half the distance between high and low water) which decrease to zero at
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#1732837528485972-493: Is never time for the fluid to "catch up" to the state it would eventually reach if the tidal force were constant—the changing tidal force nonetheless causes rhythmic changes in sea surface height. When there are two high tides each day with different heights (and two low tides also of different heights), the pattern is called a mixed semi-diurnal tide . The changing distance separating the Moon and Earth also affects tide heights. When
1053-408: Is not necessarily when the Moon is nearest to zenith or nadir , but the period of the forcing still determines the time between high tides. Because the gravitational field created by the Moon weakens with distance from the Moon, it exerts a slightly stronger than average force on the side of the Earth facing the Moon, and a slightly weaker force on the opposite side. The Moon thus tends to "stretch"
1134-502: Is not the case due to the free fall of the whole Earth, not only the oceans, towards these bodies) a different pattern of tidal forces would be observed, e.g. with a much stronger influence from the Sun than from the Moon: The solar gravitational force on the Earth is on average 179 times stronger than the lunar, but because the Sun is on average 389 times farther from the Earth, its field gradient
1215-402: Is shorter than average, and stronger tidal currents than average. Neaps result in less extreme tidal conditions. There is about a seven-day interval between springs and neaps. Tidal constituents are the net result of multiple influences impacting tidal changes over certain periods of time. Primary constituents include the Earth's rotation, the position of the Moon and Sun relative to the Earth,
1296-419: Is the time required for the Earth to rotate once relative to the Moon. Simple tide clocks track this constituent. The lunar day is longer than the Earth day because the Moon orbits in the same direction the Earth spins. This is analogous to the minute hand on a watch crossing the hour hand at 12:00 and then again at about 1: 05 + 1 ⁄ 2 (not at 1:00). The Moon orbits the Earth in the same direction as
1377-758: Is weaker. The overall proportionality is Gulf Coast of the United States The Gulf Coast of the United States , also known as the Gulf South or the South Coast , is the coastline along the Southern United States where they meet the Gulf of Mexico . The coastal states that have a shoreline on the Gulf of Mexico are Texas , Louisiana , Mississippi , Alabama , and Florida , and these are known as
1458-636: The Atlantic seaboard and the fourth largest in the U.S. overall. Two major events were turning points in the earlier history of the Gulf Coast region. The first was the American Civil War , which caused severe damage to some economic sectors in the South , including the Gulf Coast. The second event was the Galveston Hurricane of 1900 . At the end of the 19th century Galveston was, with New Orleans, one of
1539-589: The Coriolis effect , is generally clockwise in the southern hemisphere and counterclockwise in the northern hemisphere. The difference of cotidal phase from the phase of a reference tide is the epoch . The reference tide is the hypothetical constituent "equilibrium tide" on a landless Earth measured at 0° longitude, the Greenwich meridian. In the North Atlantic, because the cotidal lines circulate counterclockwise around
1620-692: The Euripus Strait and the Strait of Messina puzzled Aristotle .) Philostratus discussed tides in Book Five of The Life of Apollonius of Tyana . Philostratus mentions the moon, but attributes tides to "spirits". In Europe around 730 AD, the Venerable Bede described how the rising tide on one coast of the British Isles coincided with the fall on the other and described the time progression of high water along
1701-500: The Gulf States . The economy of the Gulf Coast area is dominated by industries related to energy, petrochemicals, fishing, aerospace, agriculture, and tourism. The large cities of the region are (from west to east) Brownsville , Corpus Christi , Houston , Galveston , Beaumont , Lake Charles , Lafayette , Baton Rouge , New Orleans , Gulfport , Biloxi , Mobile , Pensacola , Panama City , St. Petersburg , and Tampa . All are
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#17328375284851782-621: The Gulf of Mexico began production in 1938 in shallow water one mile (1.6 km) off the Louisiana coast; in 1947, a second well began to operate off the coast of Terrebonne Parish , also in Louisiana. United States v. California was filed by the Federal government against California in 1946. On 23 June 1947, the Supreme Court of the United States decided against California. The decision meant
1863-518: The North Sea . Much later, in the late 20th century, geologists noticed tidal rhythmites , which document the occurrence of ancient tides in the geological record, notably in the Carboniferous . The tidal force produced by a massive object (Moon, hereafter) on a small particle located on or in an extensive body (Earth, hereafter) is the vector difference between the gravitational force exerted by
1944-461: The Port of Houston are two of the ten busiest ports in the world by cargo volume. As of 2004, seven of the top ten busiest ports in the U.S. are on the Gulf Coast. The discovery of oil and gas deposits along the coast and offshore, combined with easy access to shipping, have made the Gulf Coast the heart of the U.S. petrochemical industry . The coast contains nearly 4,000 oil platforms . Besides
2025-499: The Sun ) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or " tidal range "). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and
2106-573: The United States Department of Justice settled the last of the tidelands controversies by ruling that the 1953 act gave control to the states of islands near the shore that were created after the states had been admitted to the Union. Tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent,
2187-489: The higher low water and the lower low water . The daily inequality is not consistent and is generally small when the Moon is over the Equator . The following reference tide levels can be defined, from the highest level to the lowest: The semi-diurnal range (the difference in height between high and low waters over about half a day) varies in a two-week cycle. Approximately twice a month, around new moon and full moon when
2268-440: The lunar theory of E W Brown describing the motions of the Moon, Arthur Thomas Doodson developed and published in 1921 the first modern development of the tide-generating potential in harmonic form: Doodson distinguished 388 tidal frequencies. Some of his methods remain in use. From ancient times, tidal observation and discussion has increased in sophistication, first marking the daily recurrence, then tides' relationship to
2349-426: The Earth rotates on its axis, so it takes slightly more than a day—about 24 hours and 50 minutes—for the Moon to return to the same location in the sky. During this time, it has passed overhead ( culmination ) once and underfoot once (at an hour angle of 00:00 and 12:00 respectively), so in many places the period of strongest tidal forcing is the above-mentioned, about 12 hours and 25 minutes. The moment of highest tide
2430-419: The Earth slightly along the line connecting the two bodies. The solid Earth deforms a bit, but ocean water, being fluid, is free to move much more in response to the tidal force, particularly horizontally (see equilibrium tide ). As the Earth rotates, the magnitude and direction of the tidal force at any particular point on the Earth's surface change constantly; although the ocean never reaches equilibrium—there
2511-570: The Earth's accumulated dynamic tidal response to the applied forces, which response is influenced by ocean depth, the Earth's rotation, and other factors. In 1740, the Académie Royale des Sciences in Paris offered a prize for the best theoretical essay on tides. Daniel Bernoulli , Leonhard Euler , Colin Maclaurin and Antoine Cavalleri shared the prize. Maclaurin used Newton's theory to show that
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2592-555: The Gulf Coast from Houston, Texas , eastward, extreme rainfall events are a significant threat, commonly from tropical weather systems, which can bring 4 to 10 or more inches of rain in a single day. In August 2017, Hurricane Harvey made landfall along the central Texas coast, then migrated to and stalled over the greater Houston area for several days, producing extreme, unprecedented rainfall totals of over 40 inches (1,000 mm) in many areas, unleashing widespread flooding. Climate scientists predict more hurricanes for Florida and
2673-477: The Gulf Coast has a summer precipitation maximum, with July or August commonly the wettest month due to the combination of frequent summer thunderstorms produced by relentless heat and humidity, and tropical weather systems, including tropical depressions, tropical storms, and hurricanes , while winter and early spring rainfall also can be heavy. This pattern is evident in southern cites as Houston , New Orleans , Mobile, Alabama , and Pensacola, Florida . However,
2754-513: The Gulf Coast was a natural magnet in the South providing access to shipping lanes and both national and international commerce. The development of sugar and cotton production (enabled by slavery ) allowed the South to prosper. By the mid-19th century the city of New Orleans , being situated as a key to commerce on the Mississippi River and in the Gulf, had become the largest U.S. city not on
2835-605: The Gulf Coast was struck by a catastrophic hurricane. Due to its immense size, Hurricane Ike caused devastation from the Louisiana coastline all the way to the Kenedy County, Texas , region near Corpus Christi . In addition, Ike caused flooding and significant damage along the Mississippi coastline and the Florida Panhandle Ike killed 112 people and left upwards of 300 people missing, never to be found. Hurricane Ike
2916-444: The Gulf Coast, predominantly Florida, is dotted with many bays and inlets. The Gulf Coast climate is humid subtropical, although Southwest Florida features a tropical climate. Much of the year is warm to hot along the Gulf Coast, while the three winter months bring periods of cool (or rarely, cold) weather mixed with mild temperatures. The area is highly vulnerable to hurricanes as well as floods and severe thunderstorms . Much of
2997-636: The Gulf Coast. In 2008 floods in Iowa destroyed the local Flood Museum which held materials from the Great Mississippi and Missouri Rivers Flood of 1993 . Before European settlers arrived in the region, the Gulf Coast was home to several pre-Columbian kingdoms which had extensive trade networks with empires such as the Aztecs and the Mississippi Mound Builders. Shark and alligator teeth and shells from
3078-643: The Gulf have been found as far north as Ohio, in the mounds of the Hopewell culture. The first Europeans to settle the Gulf Coast were primarily the French and the Spanish . The Louisiana Purchase (1803), Adams–Onís Treaty (1819) and the Texas Revolution (1835–1836) made the Gulf Coast a part of the United States during the first half of the 19th century. As the U.S. population continued to expand its frontiers westward,
3159-427: The Moon and its phases. Bede starts by noting that the tides rise and fall 4/5 of an hour later each day, just as the Moon rises and sets 4/5 of an hour later. He goes on to emphasise that in two lunar months (59 days) the Moon circles the Earth 57 times and there are 114 tides. Bede then observes that the height of tides varies over the month. Increasing tides are called malinae and decreasing tides ledones and that
3240-626: The Moon is at first quarter or third quarter, the Sun and Moon are separated by 90° when viewed from the Earth (in quadrature ), and the solar tidal force partially cancels the Moon's tidal force. At these points in the lunar cycle, the tide's range is at its minimum; this is called the neap tide , or neaps . "Neap" is an Anglo-Saxon word meaning "without the power", as in forðganges nip (forth-going without-the-power). Neap tides are sometimes referred to as quadrature tides . Spring tides result in high waters that are higher than average, low waters that are lower than average, " slack water " time that
3321-459: The Moon is closest, at perigee , the range increases, and when it is at apogee , the range shrinks. Six or eight times a year perigee coincides with either a new or full moon causing perigean spring tides with the largest tidal range . The difference between the height of a tide at perigean spring tide and the spring tide when the moon is at apogee depends on location but can be large as a foot higher. These include solar gravitational effects,
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3402-462: The Moon on the particle, and the gravitational force that would be exerted on the particle if it were located at the Earth's center of mass. Whereas the gravitational force subjected by a celestial body on Earth varies inversely as the square of its distance to the Earth, the maximal tidal force varies inversely as, approximately, the cube of this distance. If the tidal force caused by each body were instead equal to its full gravitational force (which
3483-457: The Moon's altitude (elevation) above the Earth's Equator, and bathymetry . Variations with periods of less than half a day are called harmonic constituents . Conversely, cycles of days, months, or years are referred to as long period constituents. Tidal forces affect the entire earth , but the movement of solid Earth occurs by mere centimeters. In contrast, the atmosphere is much more fluid and compressible so its surface moves by kilometers, in
3564-449: The Moon. Abu Ma'shar discussed the effects of wind and Moon's phases relative to the Sun on the tides. In the 12th century, al-Bitruji (d. circa 1204) contributed the notion that the tides were caused by the general circulation of the heavens. Simon Stevin , in his 1608 De spiegheling der Ebbenvloet ( The theory of ebb and flood ), dismissed a large number of misconceptions that still existed about ebb and flood. Stevin pleaded for
3645-663: The Northumbrian coast. The first tide table in China was recorded in 1056 AD primarily for visitors wishing to see the famous tidal bore in the Qiantang River . The first known British tide table is thought to be that of John Wallingford, who died Abbot of St. Albans in 1213, based on high water occurring 48 minutes later each day, and three hours earlier at the Thames mouth than upriver at London . In 1614 Claude d'Abbeville published
3726-518: The Sun and moon. Pytheas travelled to the British Isles about 325 BC and seems to be the first to have related spring tides to the phase of the moon. In the 2nd century BC, the Hellenistic astronomer Seleucus of Seleucia correctly described the phenomenon of tides in order to support his heliocentric theory. He correctly theorized that tides were caused by the moon , although he believed that
3807-420: The Sun, Moon, and Earth form a line (a configuration known as a syzygy ), the tidal force due to the Sun reinforces that due to the Moon. The tide's range is then at its maximum; this is called the spring tide . It is not named after the season , but, like that word, derives from the meaning "jump, burst forth, rise", as in a natural spring . Spring tides are sometimes referred to as syzygy tides . When
3888-520: The Texas coastline in particular. Earthquakes are extremely rare to the area, but a 6.0 earthquake in the Gulf of Mexico on September 10, 2006, could be felt from the cities of New Orleans to Tampa. Due to the release of greenhouse gas emissions, glaciers and ice sheets are melting and expanding the oceans. The United States coastlines are projected to rise 1 foot in three decades or between 10 and 12 inches on average by 2050. The Gulf Coast will likely see
3969-517: The Two Chief World Systems , whose working title was Dialogue on the Tides , gave an explanation of the tides. The resulting theory, however, was incorrect as he attributed the tides to the sloshing of water caused by the Earth's movement around the Sun. He hoped to provide mechanical proof of the Earth's movement. The value of his tidal theory is disputed. Galileo rejected Kepler's explanation of
4050-521: The United States approximately $ 2.6 billion in relief efforts and caused at least seven deaths. By 2051, the cost of flood damage is expected to increase by 61%, or $ 32 billion. The Gulf Coast is a major center of economic activity. The marshlands along the Louisiana and Texas coasts provide breeding grounds and nurseries for ocean life that drive the fishing and shrimping industries. The Port of South Louisiana ( Metropolitan New Orleans in Laplace ) and
4131-468: The above, the region features other important industries including aerospace and biomedical research , as well as older industries such as agriculture and — especially since the development of the Gulf Coast beginning in the 1920s and the increase in wealth throughout the United States ;— tourism . Hurricane Katrina and Hurricane Rita have destroyed a number of museums and archives in
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#17328375284854212-423: The amphidromic point, the high tide passes New York Harbor approximately an hour ahead of Norfolk Harbor. South of Cape Hatteras the tidal forces are more complex, and cannot be predicted reliably based on the North Atlantic cotidal lines. Investigation into tidal physics was important in the early development of celestial mechanics , with the existence of two daily tides being explained by the Moon's gravity. Later
4293-429: The amphidromic point. For a semi-diurnal tide the amphidromic point can be thought of roughly like the center of a clock face, with the hour hand pointing in the direction of the high water cotidal line, which is directly opposite the low water cotidal line. High water rotates about the amphidromic point once every 12 hours in the direction of rising cotidal lines, and away from ebbing cotidal lines. This rotation, caused by
4374-530: The atmosphere which did not include rotation. In 1770 James Cook 's barque HMS Endeavour grounded on the Great Barrier Reef . Attempts were made to refloat her on the following tide which failed, but the tide after that lifted her clear with ease. Whilst she was being repaired in the mouth of the Endeavour River Cook observed the tides over a period of seven weeks. At neap tides both tides in
4455-866: The biggest change, with sea levels expected to rise between 14 and 18 inches. The Global and Regional Sea Level Rise Report predicted more frequent, major and destructive high tide flooding events along with taller storm surges by 2050 after scientists determined high tide flooding has been "increasingly common" over the past few years due to the rising sea levels. The impacts are expected to be dramatic. Low-lying coastal areas are expected to experience multiple factors, including increased levels of flooding, accelerated erosion, loss of wetlands and low-lying terrestrial ecosystems, and seawater intrusion into freshwater sources. Rising sea level and erosion will also imperil critical habitats for many commercially important fisheries that depend on inshore waters for either permanent residence or nursery area. In 2021 alone rising sea levels cost
4536-586: The case of Texas, the claim to special boundary limits had been recognized by Congress in the Treaty of Guadalupe Hidalgo of 1848, which ended the Mexican–American War . The ruling for Florida was based on congressional approval of Florida's claims when the state re-entered the Union after the American Civil War . Although the other Gulf states objected to what they considered preferential treatment for Florida and Texas , no new legislation resulted. In 1963,
4617-484: The centers or major cities of their respective metropolitan areas and many of which contain large ports . The Gulf Coast is made of many inlets , bays , and lagoons . The coast is intersected by numerous rivers, the largest of which is the Mississippi River . Much of the land along the Gulf Coast is, or was, marshland . Ringing the Gulf Coast is the Gulf Coastal Plain , which reaches from Southern Texas to
4698-463: The central and southern Florida peninsula and South Texas has a pronounced winter dry season, as at Tampa and Fort Myers . On the central and southern Texas coast, winter, early spring and mid-summer are markedly drier, and September is the wettest month on average at Corpus Christi and Brownsville, Texas . Tornadoes are infrequent at the coast but do occur; however, they occur more frequently in inland portions of Gulf Coast states. Over most of
4779-410: The coast. Semi-diurnal and long phase constituents are measured from high water, diurnal from maximum flood tide. This and the discussion that follows is precisely true only for a single tidal constituent. For an ocean in the shape of a circular basin enclosed by a coastline, the cotidal lines point radially inward and must eventually meet at a common point, the amphidromic point . The amphidromic point
4860-475: The daily tides were explained more precisely by the interaction of the Moon's and the Sun's gravity. Seleucus of Seleucia theorized around 150 BC that tides were caused by the Moon. The influence of the Moon on bodies of water was also mentioned in Ptolemy 's Tetrabiblos . In De temporum ratione ( The Reckoning of Time ) of 725 Bede linked semidurnal tides and the phenomenon of varying tidal heights to
4941-531: The first to map co-tidal lines, for Great Britain, Ireland and adjacent coasts, in 1840. William Whewell expanded this work ending with a nearly global chart in 1836. In order to make these maps consistent, he hypothesized the existence of a region with no tidal rise or fall where co-tidal lines meet in the mid-ocean. The existence of such an amphidromic point , as they are now known, was confirmed in 1840 by Captain William Hewett, RN , from careful soundings in
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#17328375284855022-415: The idea that the attraction of the Moon was responsible for the tides and spoke in clear terms about ebb, flood, spring tide and neap tide , stressing that further research needed to be made. In 1609 Johannes Kepler also correctly suggested that the gravitation of the Moon caused the tides, which he based upon ancient observations and correlations. Galileo Galilei in his 1632 Dialogue Concerning
5103-464: The interaction was mediated by the pneuma . He noted that tides varied in time and strength in different parts of the world. According to Strabo (1.1.9), Seleucus was the first to link tides to the lunar attraction, and that the height of the tides depends on the moon's position relative to the Sun. The Naturalis Historia of Pliny the Elder collates many tidal observations, e.g., the spring tides are
5184-411: The largest source of short-term sea-level fluctuations, sea levels are also subject to change from thermal expansion , wind, and barometric pressure changes, resulting in storm surges , especially in shallow seas and near coasts. Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field that varies in time and space is present. For example, the shape of
5265-641: The loss of untold millions of dollars in taxes and leasing fees by the states. The states whose tidelands were thought to contain minerals objected strongly to the decision. The issue became important in the 1952 presidential campaign . The Republican candidate, Dwight D. Eisenhower , pledged legislation that would restore the tidelands to the states. Eisenhower won the election, and, in 1953, Congress passed two acts that fulfilled his campaign promise. The Submerged Lands Act extended state ownership to three geographical miles (almost exactly 3 nautical miles or 5.6 kilometres) from their actual coastline, or further if
5346-516: The major discoveries of oil in Texas and spurred on by further discoveries in the Gulf waters, has been a vehicle for development in the central and western Gulf which has spawned development on a variety of fronts in these regions. Texas in particular has benefited tremendously from this industry over the course of the 20th century and economic diversification has made the state a magnet for population and home to more Fortune 500 companies than any other U.S. state. Florida has grown as well, driven to
5427-419: The moments of slack tide differ significantly from those of high and low water. Tides are commonly semi-diurnal (two high waters and two low waters each day), or diurnal (one tidal cycle per day). The two high waters on a given day are typically not the same height (the daily inequality); these are the higher high water and the lower high water in tide tables . Similarly, the two low waters each day are
5508-412: The month is divided into four parts of seven or eight days with alternating malinae and ledones . In the same passage he also notes the effect of winds to hold back tides. Bede also records that the time of tides varies from place to place. To the north of Bede's location ( Monkwearmouth ) the tides are earlier, to the south later. He explains that the tide "deserts these shores in order to be able all
5589-514: The more to be able to flood other [shores] when it arrives there" noting that "the Moon which signals the rise of tide here, signals its retreat in other regions far from this quarter of the heavens". Later medieval understanding of the tides was primarily based on works of Muslim astronomers , which became available through Latin translation starting from the 12th century. Abu Ma'shar al-Balkhi (d. circa 886), in his Introductorium in astronomiam , taught that ebb and flood tides were caused by
5670-483: The most developed cities in the region. The city had the third busiest port in the U.S. and its financial district was known as the "Wall Street of the South". Since then the Gulf Coast has been hit with numerous other hurricanes. On August 29, 2005, Hurricane Katrina struck the Gulf Coast as a Category 3 hurricane. It was the most damaging storm in the history of the United States, causing upwards of $ 80 billion in damages, and leaving over 1,800 dead. Again in 2008
5751-423: The numerous lawsuits that emerged. The Supreme Court finally decided the issue on 31 May 1960, when it ruled that Mississippi, Alabama , and Louisiana owned the rights to the offshore lands for a distance of three geographical miles (3 nautical miles or 5.6 kilometres), and Texas and Florida owned rights to tidelands within three marine leagues (9 nautical miles or 17 kilometres), from their coastline boundaries. In
5832-420: The obliquity (tilt) of the Earth's Equator and rotational axis, the inclination of the plane of the lunar orbit and the elliptical shape of the Earth's orbit of the Sun. A compound tide (or overtide) results from the shallow-water interaction of its two parent waves. Because the M 2 tidal constituent dominates in most locations, the stage or phase of a tide, denoted by the time in hours after high water,
5913-408: The problem from the perspective of a static system (equilibrium theory), that provided an approximation that described the tides that would occur in a non-inertial ocean evenly covering the whole Earth. The tide-generating force (or its corresponding potential ) is still relevant to tidal theory, but as an intermediate quantity (forcing function) rather than as a final result; theory must also consider
5994-445: The sense of the contour level of a particular low pressure in the outer atmosphere. In most locations, the largest constituent is the principal lunar semi-diurnal , also known as the M2 tidal constituent or M 2 tidal constituent . Its period is about 12 hours and 25.2 minutes, exactly half a tidal lunar day , which is the average time separating one lunar zenith from the next, and thus
6075-402: The shape of the coastline and near-shore bathymetry (see Timing ). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure . Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides
6156-500: The solid part of the Earth is affected slightly by Earth tide , though this is not as easily seen as the water tidal movements. Four stages in the tidal cycle are named: Oscillating currents produced by tides are known as tidal streams or tidal currents . The moment that the tidal current ceases is called slack water or slack tide . The tide then reverses direction and is said to be turning. Slack water usually occurs near high water and low water, but there are locations where
6237-489: The tides. Isaac Newton (1642–1727) was the first person to explain tides as the product of the gravitational attraction of astronomical masses. His explanation of the tides (and many other phenomena) was published in the Principia (1687) and used his theory of universal gravitation to explain the lunar and solar attractions as the origin of the tide-generating forces. Newton and others before Pierre-Simon Laplace worked
6318-430: The western Florida Panhandle , while the western portions of the Gulf Coast are made up of many barrier islands and peninsulas , including the 130-mile (210 km) Padre Island along the Texas coast. These landforms protect numerous bays and inlets providing as a barrier to oncoming waves. The central part of the Gulf Coast, from eastern Texas through Louisiana, consists primarily of marshland. The eastern part of
6399-475: The work " Histoire de la mission de pères capucins en l'Isle de Maragnan et terres circonvoisines ", where he exposed that the Tupinambá people already had an understanding of the relation between the Moon and the tides before Europe. William Thomson (Lord Kelvin) led the first systematic harmonic analysis of tidal records starting in 1867. The main result was the building of a tide-predicting machine using
6480-421: Was never firmly established, but the coastal states generally proceeded as if they were the owners. Some states, such as Mississippi , directly administer these lands under the public trust doctrine . The question arose for federal nations whether the tidelands for formerly independent coastal states had been ceded to the federal union on admission, or retained. The admission of the former Republic of Texas as
6561-439: Was the third most damaging storm in the history of the United States, causing more than $ 25 billion in damage along the coast, leaving hundreds of thousands of people homeless, and sparking the largest search-and-rescue operation in U.S. history. Other than the hurricanes, the Gulf Coast has redeveloped dramatically over the course of the 20th century. The gulf coast is highly populated. The petrochemical industry, launched with
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