A raised beach, coastal terrace,Pinter, N (2010): 'Coastal Terraces, Sealevel, and Active Tectonics' (educational exercise), from 2/04/2011/ref> or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin,Pirazzoli, PA (2005a): 'Marine Terraces', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 632–633 mostly an old abrasion platform which has been lifted out of the sphere of wave activity (sometimes called "tread"). Thus, it lies above or under the current

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

, depending on the time of its formation.Strahler AH; Strahler AN (2005): ''Physische Geographie.'' Ulmer, Stuttgart, 686 p.Leser, H (ed)(2005): ‚''Wörterbuch Allgemeine Geographie.'' Westermann&Deutscher Taschenbuch Verlag, Braunschweig, 1119 p. It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side (sometimes called "riser"). Due to its generally flat shape, it is often used for

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...

structures such as settlements and

infrastructure Infrastructure is the set of facilities and systems that serve a country, city, or other area, and encompasses the services and facilities necessary for its economy, households and firms to function. Infrastructure is composed of public and pri ...

. A raised beach is an emergent coastal

landform A landform is a land feature on the solid surface of the Earth or other planetary body. They may be natural or may be anthropogenic (caused or influenced by human activity). Landforms together make up a given terrain, and their arrangement ...

. Raised beaches and marine terraces are

beach A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from Rock (geology), rock, such as sand, gravel, shingle beach, shingle, pebbles, etc., or biological s ...

es or wave-cut platforms raised above the shoreline by a relative fall in the

. Around the world, a combination of tectonic coastal uplift and

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

sea-level fluctuations has resulted in the formation of marine terrace sequences, most of which were formed during separate

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene i ...

highstands that can be correlated to

marine isotope stage Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from Oxygen isotope ratio cycle, oxygen isotope data derived from deep sea core ...

s (MIS). A marine terrace commonly retains a shoreline angle or inner edge, the slope inflection between the marine abrasion platform and the associated paleo sea cliff. The shoreline angle represents the maximum shoreline of a transgression and therefore a paleo-sea level.

Morphology

The platform of a marine terrace usually has a gradient between 1°5° depending on the former tidal range with, commonly, a linear to concave profile. The width is quite variable, reaching up to , and seems to differ between the northern and southern hemispheres.Pethick, J (1984): ''An Introduction to Coastal Geomorphology.'' Arnold&Chapman&Hall, New York, 260p. The

cliff In geography and geology, a cliff or rock face is an area of Rock (geology), rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. ...

faces that delimit the platform can vary in steepness depending on the relative roles of marine and subaerial processes.Masselink, G; Hughes, MG (2003): ''Introduction to Coastal Processes & Geomorphology.'' Arnold&Oxford University Press Inc., London, 354p. At the intersection of the former shore (wave-cut/abrasion-) platform and the rising cliff face the platform commonly retains a shoreline angle or inner edge (notch) that indicates the location of the shoreline at the time of maximum sea ingression and therefore a paleo-

. Sub-horizontal platforms usually terminate in a low-tide cliff, and it is believed that the occurrence of these platforms depends on the tidal activity. Marine terraces can extend for several tens of kilometers parallel to the

coast A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...

. Older terraces are covered by marine and/or

alluvial Alluvium (, ) is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is ...

colluvial Colluvium (also colluvial material or colluvial soil) is a general name for loose, unconsolidated sediments that have been deposited at the base of hillslopes by either rainwash, sheetwash, slow continuous downslope creep, or a variable combina ...

materials while the uppermost terrace levels usually are less well preserved. While marine terraces in areas of relatively rapid uplift rates (> 1 mm/year) can often be correlated to individual

periods or stages, those in areas of slower uplift rates may have a polycyclic origin with stages of returning

s following periods of exposure to

weathering Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...

. Marine terraces can be covered by a wide variety of

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

s with complex histories and different ages. In protected areas,

allochthonous River ecosystems are flowing waters that drain the landscape, and include the biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions of its many parts.Angelier ...

sandy parent materials from

tsunami deposit A tsunami deposit (the term tsunamiite is also sometimes used) is a sedimentary unit deposited as the result of a tsunami. Such deposits may be left onshore during the inundation phase or offshore during the 'backwash' phase. Such deposits are use ...

s may be found. Common soil types found on marine terraces include

planosols A Planosol in the World Reference Base for Soil Resources is a soil with a light-coloured, coarse-textured, surface horizon that shows signs of periodic water stagnation and abruptly overlies a dense, slowly permeable subsoil with significantl ...

and

solonetz Solonetz (, rus, Солоне́ц, p=səlɐˈnʲɛts) is a Reference Soil Group of the World Reference Base for Soil Resources (WRB). They have, within the upper 100 cm of the soil profile, a so-called "natric horizon" ("natrium" is the Lati ...

.Finkl, CW (2005): 'Coastal Soils' in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 278–302

Formation

It is now widely thought that marine terraces are formed during the separated high stands of

stages correlated to

s (MIS).

Causes

The formation of marine terraces is controlled by changes in environmental conditions and by tectonic activity during recent geological times. Changes in climatic conditions have led to eustatic sea-level oscillations and isostatic movements of the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

, especially with the changes between

glacial A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

and

periods. Processes of

eustasy The eustatic sea level (from Greek εὖ ''eû'', "good" and στάσις ''stásis'', "standing") is the distance from the center of the Earth to the sea surface. An increase of the eustatic sea level can be generated by decreasing glaciation, i ...

lead to glacioeustatic sea level fluctuations due to changes in the water volume in the oceans, and hence to regressions and transgressions of the shoreline. At times of maximum glacial extent during the last glacial period, the

was about lower compared to today. Eustatic sea level changes can also be caused by changes in the void volume of the oceans, either through sedimento-eustasy or tectono-eustasy.Ahnert, F (1996) – ''Einführung in die Geomorphologie.'' Ulmer, Stuttgart, 440 p. Processes of

isostasy Isostasy (Greek wikt:ἴσος, ''ísos'' 'equal', wikt:στάσις, ''stásis'' 'standstill') or isostatic equilibrium is the state of gravity, gravitational mechanical equilibrium, equilibrium between Earth's crust (geology), crust (or lithosph ...

involve the uplift of

continental crust Continental crust is the layer of igneous, metamorphic, and sedimentary rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as '' continental shelves''. This layer is sometimes called '' si ...

s along with their shorelines. Today, the process of glacial isostatic adjustment mainly applies to

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

glaciated areas. In

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

, for instance, the present rate of uplift reaches up to /year.Lehmkuhl, F; Römer, W (2007): 'Formenbildung durch endogene Prozesse: Neotektonik', in Gebhardt, H; Glaser, R; Radtke, U; Reuber, P (ed) ''Geographie, Physische Geographie und Humangeographie.'' Elsevier, München, pp. 316–320 In general, eustatic marine terraces were formed during separate sea-level highstands of

stages and can be correlated to marine oxygen isotopic stages (MIS). Glacioisostatic marine terraces were mainly created during stillstands of the isostatic uplift. When eustasy was the main factor for the formation of marine terraces, derived sea level fluctuations can indicate former

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

s. This conclusion has to be treated with care, as isostatic adjustments and tectonic activities can be extensively overcompensated by an eustatic sea level rise. Thus, in areas of both eustatic and isostatic or

tectonic Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

influences, the course of the relative sea level curve can be complicated.Worsley, P (1998): 'Altersbestimmung – Küstenterrassen', in Goudie, AS (ed) ''Geomorphologie, Ein Methodenhandbuch für Studium und Praxis.'' Springer, Heidelberg, pp. 528–550 Hence, most of today's marine terrace sequences were formed by a combination of tectonic coastal uplift and

sea level fluctuations. Jerky tectonic uplifts can also lead to marked terrace steps while smooth relative sea level changes may not result in obvious terraces, and their formations are often not referred to as marine terraces.

Processes

Marine terraces often result from marine erosion along rocky coastlines in temperate regions due to wave attacks and

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

carried in the waves.

Erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

also takes place in connection with

and

cavitation Cavitation in fluid mechanics and engineering normally is the phenomenon in which the static pressure of a liquid reduces to below the liquid's vapor pressure, leading to the formation of small vapor-filled cavities in the liquid. When sub ...

. The speed of erosion is highly dependent on the shoreline material (hardness of rock), the

bathymetry Bathymetry (; ) is the study of underwater depth of ocean floors ('' seabed topography''), river floors, or lake floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of wate ...

, and the

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bed ...

properties and can be between only a few millimeters per year for

granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

rocks and more than per year for volcanic ejecta. The retreat of the sea

generates a shore (wave-cut/abrasion-) platform through the process of abrasion. A relative change in the

leads to regressions or transgressions and eventually forms another terrace (marine-cut terrace) at a different altitude, while notches in the cliff face indicate short stillstands. It is believed that the terrace gradient increases with tidal range and decreases with rock resistance. In addition, the relationship between terrace width and the strength of the rock is inverse, and higher rates of uplift and subsidence as well as a higher slope of the

hinterland Hinterland is a German word meaning the 'land behind' a city, a port, or similar. Its use in English was first documented by the geographer George Chisholm in his ''Handbook of Commercial Geography'' (1888). Originally the term was associated wi ...

increase the number of terraces formed during a certain time. Furthermore, shore platforms are formed by

denudation Denudation is the geological process in which moving water, ice, wind, and waves erode the Earth's surface, leading to a reduction in elevation and in relief of landforms and landscapes. Although the terms erosion and denudation are used interchang ...

and marine-built terraces arise from accumulations of materials removed by shore erosion. Thus, a marine terrace can be formed by both

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

and accumulation. However, there is an ongoing debate about the roles of wave erosion and

in the formation of shore platforms. Reef flats or uplifted coral reefs are another kind of marine terrace found in intertropical regions. They are a result of biological activity, shoreline advance and accumulation of

reef A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...

materials. While a terrace sequence can date back hundreds of thousands of years, its degradation is a rather fast process. A deeper transgression of cliffs into the shoreline may destroy previous terraces; but older terraces might be decayed or covered by deposits, colluvia or

alluvial fan An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to Semi-arid climate, semiar ...

s. Erosion and backwearing of slopes caused by incisive streams play another important role in this degradation process.

Land and sea level history

The total displacement of the shoreline relative to the age of the associated interglacial stage allows the calculation of a mean uplift rate or the calculation of eustatic level at a particular time if the uplift is known. To estimate vertical uplift, the eustatic position of the considered paleo sea levels relative to the present one must be known as precisely as possible. Current

chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the deter ...

relies principally on

relative dating Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e., estimated age). In geology, rock or superficial d ...

based on geomorphologic criteria, but in all cases, the shoreline angle of the marine terraces is associated with numerical ages. The best-represented terrace worldwide is the one correlated to the last interglacial maximum ( MIS 5e). The age of MISS 5e is arbitrarily fixed to range from 130 to 116 ka but is demonstrated to range from 134 to 113 ka in

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

and

Barbados Barbados, officially the Republic of Barbados, is an island country in the Atlantic Ocean. It is part of the Lesser Antilles of the West Indies and the easternmost island of the Caribbean region. It lies on the boundary of the South American ...

with a peak from 128 to 116 ka on tectonically stable coastlines. Older marine terraces well represented in worldwide sequences are those related to MIS 9 (~303–339 ka) and 11 (~362–423 ka). Compilations show that sea level was 3 ± 3 meters higher during MIS 5e, MIS 9 and 11 than during the present one and −1 ± 1 m to the present one during MIS 7. Consequently, MIS 7 (~180-240 ka) marine terraces are less pronounced and sometimes absent. When the elevations of these terraces are higher than the uncertainties in paleo-eustatic sea level mentioned for the

Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

and

Late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division ...

, these uncertainties don't affect on overall interpretation. The sequence can also occur where the accumulation of

ice sheets In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets ...

has depressed the land so that when the ice sheets melt the land readjusts with time thus raising the height of the beaches (glacial-isostatic rebound) and in places where co-seismic uplift occurs. In the latter case, the terrace is not correlated with sea-level highstands even if co-seismic terraces are known only for the Holocene.

Mapping and surveying

For exact interpretations of the morphology, extensive datings, surveying and mapping of marine terraces are applied. This includes

stereoscopic Stereoscopy, also called stereoscopics or stereo imaging, is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word ''stereoscopy'' derives . Any stereoscopic image is ...

aerial photographic interpretation (ca. 1 : 10,000 – 25,000), on-site inspections with

topographic map In modern mapping, a topographic map or topographic sheet is a type of map characterized by large- scale detail and quantitative representation of relief features, usually using contour lines (connecting points of equal elevation), but histori ...

s (ca. 1 : 10,000) and analysis of eroded and accumulated material. Moreover, the exact altitude can be determined with an aneroid barometer or preferably with a levelling instrument mounted on a tripod. It should be measured with an accuracy of and at about every , depending on the

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the landforms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

. In remote areas, the techniques of

photogrammetry Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant ima ...

and

tacheometry Tacheometry (; from Greek for "quick measure") is a system of rapid surveying, by which the horizontal and vertical positions of points on the Earth's surface relative to one another are determined using a tacheometer (a form of theodolite). It ...

can be applied.

Correlation and dating

Different methods for dating and correlation of marine terraces can be used and combined.

Correlational dating

The morphostratigraphic approach focuses especially in regions of

marine regression A marine regression is a geological process occurring when areas of submerged seafloor are exposed during a drop in sea level. The opposite event, marine transgression, occurs when flooding from the sea covers previously-exposed land. Descript ...

on the altitude as the most important criterion to distinguish coastlines of different ages. Moreover, individual marine terraces can be correlated based on their size and continuity. Also, paleo-soils as well as

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

, eolian and

periglacial Periglaciation (adjective: "periglacial", referring to places at the edges of glacial areas) describes geomorphic processes that result from seasonal thawing and freezing, very often in areas of permafrost. The meltwater may refreeze in ice wedg ...

landforms and

s may be used to find correlations between terraces. On New Zealand's North Island, for instance,

tephra Tephra is fragmental material produced by a Volcano, volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, ...

and

loess A loess (, ; from ) is a clastic rock, clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loesses or similar deposition (geology), deposits. A loess ...

were used to date and correlate marine terraces. At the terminus advance of former

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

s marine terraces can be correlated by their size, as their width decreases with age due to the slowly thawing glaciers along the coastline. The

lithostratigraphic Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology. In general, strata are primarily igneous ...

approach uses typical sequences of

and

rock strata In geology and related fields, a stratum (: strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as ...

to prove sea-level fluctuations based on an alternation of terrestrial and marine sediments or

littoral The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely i ...

and shallow marine sediments. Those strata show typical layers of transgressive and regressive patterns. However, an

unconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...

in the sediment sequence might make this analysis difficult. The biostratigraphic approach uses remains of organisms which can indicate the age of a marine terrace. For that, often

mollusc shell The mollusc (or mollusk) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes. Not all shelled ...

foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

are used. Especially

Mollusca Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

can show specific properties depending on their depth of

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to th ...

. Thus, they can be used to estimate former water depths. Marine terraces are often correlated to marine oxygen isotopic stages (MIS) and can also be roughly dated using their

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

position.

Direct dating

There are various methods for the direct dating of marine terraces and their related materials. The most common method is ¹⁴C

radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for Chronological dating, determining the age of an object containing organic material by using the properties of carbon-14, radiocarbon, a radioactive Isotop ...

,Schellmann, G; Brückner, H (2005): 'Geochronology', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 467–472 which has been used, for example, on the North Island of New Zealand to date several marine terraces. It utilizes terrestrial biogenic materials in coastal

s, such as

s, by analyzing the ¹⁴C

isotope Isotopes are distinct nuclear species (or ''nuclides'') of the same chemical element. They have the same atomic number (number of protons in their Atomic nucleus, nuclei) and position in the periodic table (and hence belong to the same chemica ...

. In some cases, however, dating based on the ²³⁰Th/ ²³⁴U ratio was applied, in case detrital contamination or low

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

concentrations made finding a high-resolution dating difficult. In a study in southern Italy,

paleomagnetism Paleomagnetism (occasionally palaeomagnetism) is the study of prehistoric Earth's magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain ...

was used to carry out paleomagnetic datingsBrückner, H (1980): 'Marine Terrassen in Süditalien. Eine quartärmorphologische Studie über das Küstentiefland von Metapont', ''Düsseldorfer Geographische Schriften,'' 14, Düsseldorf, Germany: Düsseldorf University and

luminescence dating Luminescence dating refers to a group of chronological dating methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event ...

(OSL) was used in different studies on the

San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...

and on the

Eupcheon Fault in

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

. In the last decade, the dating of marine terraces has been enhanced since the arrival of the terrestrial cosmogenic nuclides method, particularly through the use of ¹⁰Be and ²⁶Al cosmogenic isotopes produced on site. These isotopes record the duration of surface exposure to

cosmic rays Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar ...

. This exposure age reflects the age of abandonment of a marine terrace by the sea. To calculate the eustatic

for each dated terrace, it is assumed that the eustatic sea-level position corresponding to at least one marine terrace is known and that the uplift rate has remained essentially constant in each section.

Relevance for other research areas

Marine terraces south of Choapa River in Chile. These terraces have been studied among others by Roland Paskoff. Marine terraces play an important role in the research on tectonics and earthquakes. They may show patterns and rates of tectonic uplift and thus may be used to estimate the tectonic activity in a certain region. In some cases the exposed secondary landforms can be correlated with known seismic events such as the

1855 Wairarapa earthquake The 1855 Wairarapa earthquake occurred on 23 January at about 9.17 p.m., affecting much of the Cook Strait area of New Zealand, including Marlborough in the South Island and Wellington and the Wairarapa in the North Island. In Wellington, cl ...

on the Wairarapa Fault near

Wellington Wellington is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the third-largest city in New Zealand (second largest in the North Island ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

which produced a uplift.Crozier, MJ; Preston NJ (2010): 'Wellington's Tectonic Landscape: Astride a Plate Boundary' in Migoń, P. (ed) ''Geomorphological Landscapes of the World.'' Springer, New York, pp. 341–348 This figure can be estimated from the vertical offset between raised shorelines in the area. Furthermore, with the knowledge of eustatic

fluctuations, the speed of isostatic uplift can be estimatedPress, F; Siever, R (2008): ''Allgemeine Geologie.'' Spektrum&Springer, Heidelberg, 735 p. and eventually the change of relative sea levels for certain regions can be reconstructed. Thus, marine terraces also provide information for the research on

and trends in future

changes. When analyzing the morphology of marine terraces, it must be considered, that both

and

can influence on the formation process. This way can be assessed, whether there were changes in sea level or whether tectonic activities took place.

Prominent examples

Raised beaches are found in a wide variety of coast and geodynamical backgrounds such as

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

on the Pacific coasts of

South South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both west and east. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

passive margin A passive margin is the transition between Lithosphere#Oceanic lithosphere, oceanic and Lithosphere#Continental lithosphere, continental lithosphere that is not an active plate continental margin, margin. A passive margin forms by sedimentatio ...

of the Atlantic coast of South America, collision context on the Pacific coast of Kamchatka,

Papua New Guinea Papua New Guinea, officially the Independent State of Papua New Guinea, is an island country in Oceania that comprises the eastern half of the island of New Guinea and offshore islands in Melanesia, a region of the southwestern Pacific Ocean n ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, passive margin of the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by South China, in the west by the Indochinese Peninsula, in the east by the islands of Taiwan island, Taiwan and northwestern Philippines (mainly Luz ...

coast, on west-facing Atlantic coasts, such as

Donegal Bay Donegal Bay () is an inlet (or bay) in the northwest of Ireland. Three Counties of Ireland, counties – County Donegal, Donegal to the north and west, County Leitrim, Leitrim and County Sligo, Sligo to the south – have shorelines on ...

County Cork County Cork () is the largest and the southernmost Counties of Ireland, county of Republic of Ireland, Ireland, named after the city of Cork (city), Cork, the state's second-largest city. It is in the Provinces of Ireland, province of Munster ...

and

County Kerry County Kerry () is a Counties of Ireland, county on the southwest coast of Republic of Ireland, Ireland, within the Provinces of Ireland, province of Munster and the Southern Region, Ireland, Southern Region. It is bordered by two other countie ...

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

;

Bude Bude (, locally or ; Cornish language, Cornish ) is a seaside town in north Cornwall, England, in the civil parish of Bude-Stratton and at the mouth of the River Neet (also known locally as the River Strat). It was sometimes formerly known as ...

Widemouth Bay Widemouth Bay () is a bay, beach and small village on the Atlantic Ocean, Atlantic Atlantic coast of Cornwall, coast of Cornwall, England, United Kingdom. It is about 3 miles (5 km) south of Bude. This stretch of coast is steeped in the ...

, Crackington Haven,

Tintagel Tintagel () or Trevena (, meaning ''Village on a Mountain'') is a civil parishes in England, civil parish and village situated on the Atlantic Ocean, Atlantic coast of Cornwall, England, United Kingdom. The village and nearby Tintagel Castle ...

, Perranporth and St Ives in

Cornwall Cornwall (; or ) is a Ceremonial counties of England, ceremonial county in South West England. It is also one of the Celtic nations and the homeland of the Cornish people. The county is bordered by the Atlantic Ocean to the north and west, ...

, the

Vale of Glamorgan The Vale of Glamorgan ( ), locally referred to as ''The Vale'', is a Principal areas of Wales, county borough in the South East Wales, south-east of Wales. It borders Bridgend County Borough to the west, Cardiff to the east, Rhondda Cynon Taf t ...

Gower Peninsula The Gower Peninsula (), or simply Gower (), is a peninsula in the South West Wales, south-west of Wales. It is the most westerly part of the historic county of Glamorgan, and is now within the City and County of Swansea. It projects towards th ...

Pembrokeshire Pembrokeshire ( ; ) is a Principal areas of Wales, county in the South West Wales, south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and otherwise by the sea. Haverfordwest is the largest town and ...

and

Cardigan Bay Cardigan Bay () is a large inlet of the Irish Sea, indenting the west coast of Wales between Bardsey Island, Gwynedd in the north, and Strumble Head, Pembrokeshire at its southern end. It is the largest bay in Wales. Geography Cardigan Bay ha ...

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

, Jura and the

Isle of Arran The Isle of Arran (; ) or simply Arran is an island off the west coast of Scotland. It is the largest island in the Firth of Clyde and the seventh-largest Scottish island, at . Counties of Scotland, Historically part of Buteshire, it is in the ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

Finistère Finistère (, ; ) is a Departments of France, department of France in the extreme west of Brittany. Its prefecture is Quimper and its largest city is Brest, France, Brest. In 2019, it had a population of 915,090.Brittany Brittany ( ) is a peninsula, historical country and cultural area in the north-west of modern France, covering the western part of what was known as Armorica in Roman Gaul. It became an Kingdom of Brittany, independent kingdom and then a Duch ...

and Galicia in Northern Spain and at Squally Point in Eatonville, Nova Scotia within the Cape Chignecto Provincial Park. Other important sites include various coasts of

, e.g.

Turakirae Head Turakirae Head is a promontory and scientific reserve on the southern coast of New Zealand's North Island. It is located at the western end of Palliser Bay, 20 kilometres southeast of Wellington, at the southern end of the Remutaka Range. The he ...

near

being one of the world's best and most thoroughly studied examples. Also along the

Cook Strait Cook Strait () is a strait that separates the North Island, North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is wide at its narrowest point,McLintock, ...

, there is a well-defined sequence of uplifted marine terraces from the late

at Tongue Point. It features a well-preserved lower terrace from the last

, a widely eroded higher terrace from the penultimate interglacial and another still higher terrace, which is nearly completely decayed. Furthermore, on New Zealand's North Island at the eastern

Bay of Plenty The Bay of Plenty () is a large bight (geography), bight along the northern coast of New Zealand's North Island. It stretches from the Coromandel Peninsula in the west to Cape Runaway in the east. Called ''Te Moana-a-Toitehuatahi'' (the Ocean ...

, a sequence of seven marine terraces has been studied. Along many coasts of the mainland and islands around the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

, marine terraces are typical coastal features. An especially prominent marine terraced coastline can be found north of Santa Cruz, near Davenport,

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, where terraces probably have been raised by repeated slip earthquakes on the

.Pirazzoli, PA (2005b.): 'Tectonics and Neotectonics', Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 941–948 Hans Jenny famously researched the

pygmy forest A "natural National Park in the Philippines, a UNESCO World Heritage Site file:Mount Kemiri (8187817161).jpg, An elfin forest in Sumatra's Gunung Leuser National Park Dwarf forest, elfin forest, or pygmy forest is an uncommon ecosystem feat ...

s of the Mendocino and Sonoma county marine terraces. The marine terrace's "ecological staircase" of

Salt Point State Park Salt Point State Park is a state park in Sonoma County, California, Sonoma County, California, United States. The park covers on the coast of Northern California, with of hiking trails and over of a rough rocky coastline including Salt Point w ...

is also bound by the San Andreas Fault. Along the coasts of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

marine terraces are present, where the highest ones are situated where plate margins lie above subducted oceanic ridges and the highest and most rapid rates of uplift occur. At Cape Laundi,

Sumba Island Sumba (; ), natively also spelt as Humba, Hubba, Suba, or Zuba (in Sumba languages) is an List of islands of Indonesia, Indonesian island (part of the Lesser Sunda Islands, Lesser Sunda Archipelago group) located in the Eastern Indonesia and ad ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

an ancient patch reef can be found at above

as part of a sequence of coral reef terraces with eleven terraces being wider than . The coral marine terraces at

Huon Peninsula Huon Peninsula is a large rugged peninsula on the island of New Guinea in Morobe Province, eastern Papua New Guinea. It is named after French explorer Jean-Michel Huon de Kermadec. The peninsula is dominated by the steep Saruwaged and Finist ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

, which extend over and rise over above present

are currently on

UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...

's tentative list for

world heritage sites World Heritage Sites are landmarks and areas with legal protection under an international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural heritag ...

under the name ''Houn Terraces - Stairway to the Past.''UNESCO (2006): ''Huon Terraces – Stairway to the Past.'' from https://whc.unesco.org/en/tentativelists/5066/ 3/04/2011/ref> Other considerable examples include marine terraces rising to on some

Philippine Islands The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

Eisma, D (2005): 'Asia, eastern, Coastal Geomorphology', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 67–71 and along the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

Coast of

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

, especially in

Tunisia Tunisia, officially the Republic of Tunisia, is a country in the Maghreb region of North Africa. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia also shares m ...

, rising to .Orme, AR (2005): 'Africa, Coastal Geomorphology', in Schwartz, ML (ed) ''Encyclopedia of Coastal Science.'' Springer, Dordrecht, pp. 9–21

Related coastal geography

Uplift can also be registered through tidal notch sequences. Notches are often portrayed as lying at sea level; however, notch types form a continuum from wave notches formed in quiet conditions at sea level to surf notches formed in more turbulent conditions and as much as above sea level. As stated above, there was at least one higher sea level during the Holocene, so some notches may not contain a tectonic component in their formation.

References

External links

Notes
at NAHSTE * US Geological Survey Marine Terrace Fact Sheet
Wikimedia linkUSGS link
{{DEFAULTSORT:Raised Beach Coastal and oceanic landforms Geomorphology Oceanographical terminology Coastal geography Beaches Lacustrine landforms