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 Abrasion is a process of erosion which occurs when material being transported wears away at a surface over time. It is the process of friction caused by scuffing, scratching, wearing down, marring, and rubbing away of materials. The intensity of ...

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 average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardis ...

, 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 Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human i ...

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 priv ...

. A raised beach is an emergent coastal

landform A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, ...

. 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, such as sand, gravel, shingle, pebbles, etc., or biological sources, such as mollusc s ...

es or

wave-cut platform A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by erosion. Wave-cut platforms are often most o ...

s raised above the shoreline by a relative fall in the

Path from The Doon to King's Cave, Arran

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). It follows the Neogene Period and spans from 2.58 million year ...

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 data reflecting changes in temperature derived from data f ...

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 Northern may refer to the following: Geography * North, a point in direction * Northern Europe, the northern part or region of Europe * Northern Highland, a region of Wisconsin, United States * Northern Province, Sri Lanka * Northern Range, a r ...

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 is an area of 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. Cliffs are common on co ...

faces that delimit the platform can vary in steepness depending on the relative roles of marine and

subaerial In natural science, subaerial (literally "under the air"), has been used since 1833,Subaerial
in the Merriam ...

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 tidal activity. Marine terraces can extend for several tens of kilometers parallel to the

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

. Older terraces are covered by marine and/or

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') 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. ...

or colluvial 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, and biological organisms. Weathering occurs '' in situ'' (on site, with little or no movement ...

. Marine terraces can be covered by a wide variety of

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

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

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

solonetz Solonetz ( uk, Солонець, 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" ( ...

.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 highstands 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 Earth's thin outer shell of rock, referring to less than 1% of Earth's radius and volume. It is the top component of the lithosphere, a division of Earth's layers that includes the crust and the upper part of the mantle. The ...

, especially with the changes between

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

and

periods. Processes of eustasy lead to glacioeustatic sea level fluctuations due to changes of 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 ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its ...

involve the uplift of

continental crust Continental crust is the layer of igneous, sedimentary, and metamorphic 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 '' sial'' be ...

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

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

glaciated areas. In

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and S ...

, 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

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 Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound ...

. When eustasy was the main factor for the formation of marine terraces, derived

fluctuations can indicate former

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

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

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents ...

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

uplifts can also lead to marked terrace steps while smooth relative

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 attack and

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

carried in the waves.

Erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

also takes place in connection with

and

cavitation Cavitation is a phenomenon in which the static pressure of a liquid reduces to below the liquid's vapour pressure, leading to the formation of small vapor-filled cavities in the liquid. When subjected to higher pressure, these cavities, ca ...

. 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''), lake floors, or river floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of water ...

, 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 be ...

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

granitic A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz- ...

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 of 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 associate ...

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

denudation Denudation is the geological processes 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 interc ...

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 water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is d ...

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 processes—deposition of sand, wave erosion planing down rock ...

materials. While a terrace sequence can date back hundreds of thousands of years, its degradation is a rather fast process. On the one hand a deeper transgression of cliffs into the shoreline may completely destroy previous terraces; on the other hand 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 semiarid climates, but a ...

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 calculation of a mean uplift rate or the calculation of eustatic level at a particular time if the uplift is known. In order 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. Our

chronology Chronology (from Latin ''chronologia'', from Ancient Greek , ''chrónos'', "time"; and , ''-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 even ...

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 dep ...

based on geomorphologic criteria, but in all cases we associated the shoreline angle of the marine terraces with numerical ages. The best-represented terrace worldwide is the one correlated to the last interglacial maximum ( MIS 5e). 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 ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

and

Barbados Barbados is an island country in the Lesser Antilles of the West Indies, in the Caribbean region of the Americas, and the most easterly of the Caribbean Islands. It occupies an area of and has a population of about 287,000 (2019 estima ...

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 Marine Isotope Stage 9 (MIS 9) is a Marine Isotope Stage in the geological record. It is the final period of the Lower Paleolithic, and lasts from 337,000 to 300,000 years ago according to Lisiecki and Raymo's LR04 Benthic Stack, which has been ado ...

(~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 geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

and

Late Pleistocene The Late Pleistocene is an unofficial age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a stratigraphic perspective. It is intended to be the fourth division of the Pleistocene Epoch withi ...

, these uncertainties have no effect on overall interpretation. Sequence can also occur where the accumulation of ice sheets have depressed the land so that when the ice sheets melts the land readjusts with time thus raising the height of the beaches (glacio-isostatic rebound) and in places where co-seismic uplift occur. In the latter case, the terrace are not correlated with sea level highstand even if co-seismic terrace are known only for the Holocene.

Mapping and surveying

For exact interpretations of the morphology, extensive datings, surveying and mapping of marine terraces is 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 A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

or preferably with a levelling instrument mounted on a tripod. It should be measured with the 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 land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sc ...

. 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 without using a chain or tape, or a separate l ...

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 above the sea level. The opposite event, marine transgression, occurs when flooding from the sea covers previously-exposed land. Evidence of marin ...

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 In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

, eolian and periglacial 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 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, they r ...

and

loess Loess (, ; from german: Löss ) is a 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 loess or similar deposits. Loess is a periglacial or aeoli ...

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

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

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 igneou ...

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 e ...

to prove

fluctuations on the basis of an alternation of terrestrial and

marine sediments Marine sediment, or ocean sediment, or seafloor sediment, are deposits of insoluble particles that have accumulated on the seafloor. These particles have their origins in soil and rocks and have been transported from the land to the sea, mai ...

or littoral 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 Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Bio ...

approach uses remains of organisms which can indicate the age of a marine terrace. For that, often

mollusc shell The mollusc (or molluskOften spelled mollusk shell in the USA; the spelling "mollusc" are preferred by ) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, wh ...

foraminifera Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly ...

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...

are used. Especially

Mollusca Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

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 the ...

. 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: lithostra ...

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 determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...

,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 two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass num ...

. 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 with the 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. Uranium is weak ...

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

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

paleomagnetism Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in roc ...

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 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 occurred. It uses var ...

(OSL) was used in different studies on the

San Andreas Fault The San Andreas Fault is a continental transform fault that extends roughly through California. It forms the tectonic boundary between the Pacific Plate and the North American Plate, and its motion is right-lateral strike-slip (horizontal) ...

and on the

Eupcheon Fault in

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

. In the last decade, the dating of marine terraces has been enhanced since the arrival of terrestrial cosmogenic nuclides method, and 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 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 System in our ...

. This exposure age reflects the age of abandonment of a marine terrace by the sea. In order 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, close ...

on the Wairarapa Fault near

Wellington Wellington ( mi, Te Whanganui-a-Tara or ) 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 second-largest city in New Zealand by ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

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 eustasy and

can have an 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 background such as

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

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 east and west. 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 and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

passive margin A passive margin is the transition between oceanic and continental lithosphere that is not an active plate margin. A passive margin forms by sedimentation above an ancient rift, now marked by transitional lithosphere. Continental rifting cre ...

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

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

, 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 the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Ph ...

coast, on west-facing Atlantic coasts, such as Donegal Bay,

County Cork County Cork ( ga, Contae Chorcaí) is the largest and the southernmost county of Ireland, named after the city of Cork, the state's second-largest city. It is in the province of Munster and the Southern Region. Its largest market towns a ...

and

County Kerry County Kerry ( gle, Contae Chiarraí) is a county in Ireland. It is located in the South-West Region and forms part of the province of Munster. It is named after the Ciarraige who lived in part of the present county. The population of the co ...

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

; Bude, Widemouth Bay,

Crackington Haven Crackington Haven ( kw, Porthkragen, meaning "sandstone cove") is a coastal village in Cornwall, England, United Kingdom. It is in the civil parish of St Gennys at at the head of a cove on the Atlantic coast. The village is seven miles ( ...

Tintagel Tintagel () or Trevena ( kw, Tre war Venydh, meaning ''Village on a Mountain'') is a civil parish and village situated on the Atlantic coast of Cornwall, England. The village and nearby Tintagel Castle are associated with the legends surroun ...

Perranporth Perranporth ( kw, Porthperan) is a seaside resort town on the north coast of Cornwall, England, United Kingdom. It is 1 mile east of the St Agnes Heritage Coastline, and around 8 miles south-west of Newquay. Perranporth and its long beach ...

and St Ives in

Cornwall Cornwall (; kw, Kernow ) is a Historic counties of England, historic county and Ceremonial counties of England, ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people ...

, the

Vale of Glamorgan The Vale of Glamorgan ( cy, Bro Morgannwg ), often referred to as The Vale, is a county borough in the south-east of Wales. It borders Bridgend County Borough to the west, Cardiff to the east, Rhondda Cynon Taf to the north, and the Bristol ...

Gower Peninsula Gower ( cy, Gŵyr) or the Gower Peninsula () in southwest Wales, projects towards the Bristol Channel. It is the most westerly part of the historic county of Glamorgan. In 1956, the majority of Gower became the first area in the United Kingdom ...

Pembrokeshire Pembrokeshire ( ; cy, Sir Benfro ) is a county in the south-west of Wales. It is bordered by Carmarthenshire to the east, Ceredigion to the northeast, and the rest by sea. The county is home to Pembrokeshire Coast National Park. The Park oc ...

and

Cardigan Bay Cardigan Bay ( cy, Bae Ceredigion) 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. Geo ...

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...

, Jura and the

Isle of Arran The Isle of Arran (; sco, Isle o Arran; gd, Eilean Arainn) 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 . Historically part of Buteshi ...

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to ...

Finistère Finistère (, ; br, Penn-ar-Bed ) is a department of France in the extreme west of Brittany. In 2019, it had a population of 915,090.

Brittany Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo: ''Bertaèyn'' ) is a peninsula, historical country and cultural area in the west of modern France, covering the western part of what was known as Armorica during the period ...

and

Galicia Galicia may refer to: Geographic regions * Galicia (Spain), a region and autonomous community of northwestern Spain ** Gallaecia, a Roman province ** The post-Roman Kingdom of the Suebi, also called the Kingdom of Gallaecia ** The medieval King ...

Northern Spain Spain is a country located in southwestern Europe occupying most (about 82 percent) of the Iberian Peninsula. It also includes a small exclave inside France called Llívia, as well as the Balearic Islands in the Mediterranean, the Canary Isla ...

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 near

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

Cook Strait Cook Strait ( mi, Te Moana-o-Raukawa) separates the 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, A ...

, 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 ( mi, Te Moana-a-Toi) is a region of New Zealand, situated around a bight of the same name in the northern coast of the North Island. The bight stretches 260 km from the Coromandel Peninsula in the west to Cape Runaw ...

, a sequence of seven marine terraces has been studied. Along many coasts of 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 definition, to Antarctica) in the south, and is bounded by the contine ...

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

Davenport Davenport may refer to: Places Australia *Davenport, Northern Territory, a locality *Hundred of Davenport, cadastral unit in South Australia **Davenport, South Australia, suburb of Port Augusta ** District Council of Davenport, former local govern ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, 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 In anthropology, pygmy peoples are ethnic groups whose average height is unusually short. The term pygmyism is used to describe the phenotype of endemic short stature (as opposed to disproportionate dwarfism occurring in isolated cases in a ...

s of the Mendocino and Sonoma county marine terraces. The marine terrace's "ecological staircase" of Salt Point State Park 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 relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

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 ( id, Pulau Sumba) is an island in eastern Indonesia. It is one of the Lesser Sunda Islands and is in the province of East Nusa Tenggara. Sumba has an area of , and the population was 779,049 at the 2020 Census; the official estimate as at ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

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 Finisterr ...

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...

, which extend over and rise over above present

are currently on

UNESCO The United Nations Educational, Scientific and Cultural Organization is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) aimed at promoting world peace and security through international coope ...

’s tentative list for

world heritage sites A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for ...

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 up to on some

Philippine Islands The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on ...

Coast of

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

, especially in

Tunisia ) , image_map = Tunisia location (orthographic projection).svg , map_caption = Location of Tunisia in northern Africa , image_map2 = , capital = Tunis , largest_city = capital , ...

, rising up 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 actually 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 that some notches may not contain a tectonic component in their formation.

References

External links

Notes
at

NAHSTE The Navigational Aids for the History of Science, Technology, and the Environment Project (NAHSTE) was a research archives/manuscripts cataloguing project based at the University of Edinburgh. Following a proposal led by Arnott Wilson in 1999, t ...

* 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