Newlyn Tidal Observatory

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Newlyn Tidal Observatory
GLOSS ID 241
Newlyn harbour light 342.jpg
View of Newlyn Harbour with the lighthouse and Tidal Observatory to its right
Type Tide gauge
Location Newlyn, Cornwall, England
Coordinates 50°06′11″N5°32′34″W / 50.103000°N 5.542806°W / 50.103000; -5.542806
Built1915
Owner National Oceanography Centre [1]
Website ntslf.org/tgi/portinfo?port=Newlyn OOjs UI icon edit-ltr-progressive.svg
Listed Building – Grade II
Official nameNewlyn tidal observatory and part of the south pier
Designated11 December 2018
Reference no. 1460225
Cornwall UK location map.svg
Red pog.svg
Location of Newlyn Tidal Observatory in Cornwall

Newlyn Tidal Observatory is a grade II listed tide gauge hut on the South Pier in Newlyn, Cornwall in England. Measurements of sea level taken at the observatory between 1915 and 1921 were used to define the reference level, Ordnance Datum Newlyn, for height measurement on the British mainland. The tide gauge has collected over 100 years of observations which has significantly contributed to studies in sea level science.

Contents

Building and location

The observatory is a building situated behind the lighthouse at the end of the South Pier in Newlyn, near Penzance, in Cornwall. Constructed of concrete, it has the appearance of a small hut and is painted in red and white stripes. [2] Inside the building is an Ordnance Survey benchmark, constituted of a brass bolt (OSBM SW 4676 2855), and a 1.6-metre (5 ft 3 in) diameter stilling well set into the pier which has ocean access via an inlet. [3] [4] [5]

History

Newlyn South Pier Light (7342).jpg
Newlyn South Pier Light (7342).jpg
The observatory building in 2011

The Ordnance Survey established the observatory in 1915 to contribute to the measurement of a national vertical datum defined by mean sea level. The subsequent 6-year measurement campaign at the observatory, conducted from 1 May 1915 to 30 April 1921, determined the value of mean sea level as 4.751 m (15.59 ft) below the level of the brass bolt benchmark inside the hut. Due to the stable underlying granite bedrock, the proximity to the open ocean, and the absence of rivers, the observations at Newlyn were selected as the basis, or ordnance datum, for elevation measurements across Great Britain. To realise the reference datum across the country, in the early twentieth century spirit levelling techniques were used to measure a national network of circa 200 fundamental benchmarks, all referenced to the Newlyn brass bolt. [2] [3] [6] [7]

From 1915 to 1983 the observatory measured sea level using a float in the stilling well, along with a gauge supplied by Cary and Porter. With advances in technology, an Aanderaa pressure gauge was installed in 1981 to operate alongside the well gauge. Since 1983 the primary sensor has been a bubbler pressure gauge. [3] [8]

The Ordnance Survey operated the tide gauge until 1983, when the Natural Environment Research Council took over the management. [3] The observatory was designated as grade II listed status by Historic England in December 2018. [9] As of 2023 the observatory is operated by the National Oceanography Centre, and funding support is contributed by the UK Environment Agency. [1] [3]

Impact

Time series plot of monthly Mean Sea Level at Newlyn, Cornwall, 1915 to 2023 Newlyn Monthly Mean Sea Level 1915 - 2023 (m).png
Time series plot of monthly Mean Sea Level at Newlyn, Cornwall, 1915 to 2023

The 6 years of observations captured at the observatory up to 1921 continue to define the height reference system for Great Britain, with varied applications including flood planning, understanding air pollution, infrastructure design, and deliveries by unmanned aerial vehicles. [2]

In 2016 Bradshaw et al. published an article to commemorate 100 years of sea level measurements at the Newlyn observatory, in particular highlighting how the collected data had "played a fundamental role in UK geodesy and oceanography", [3] and in 2021 the impact of the data on ocean and climate change studies was noted. [7] [10]

See also

Related Research Articles

<span class="mw-page-title-main">Geodesy</span> Science of planetary measurement

Geodesy or geodetics is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D. It is called planetary geodesy when studying other astronomical bodies, such as planets or circumplanetary systems. Geodesy is an earth science as well as a discipline of applied mathematics, and many consider the study of Earth's shape and gravity to be central to the science.

<span class="mw-page-title-main">Geographic coordinate system</span> System to specify locations on Earth

A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. It is the simplest, oldest and most widely used of the various spatial reference systems that are in use, and forms the basis for most others. Although latitude and longitude form a coordinate tuple like a cartesian coordinate system, the geographic coordinate system is not cartesian because the measurements are angles and are not on a planar surface.

<span class="mw-page-title-main">Sea level</span> Geographical reference point from which various heights are measured

Mean 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 datum – a standardised geodetic datum – that is used, for example, as a chart datum in cartography and marine navigation, or, in aviation, as the standard sea level at which atmospheric pressure is measured to calibrate altitude and, consequently, aircraft flight levels. A common and relatively straightforward mean sea-level standard is instead a long-term average of tide gauge readings at a particular reference location.

<span class="mw-page-title-main">Ordnance Survey National Grid</span> System of geographic grid references used in Great Britain

The Ordnance Survey National Grid reference system (OSGB), also known as British National Grid (BNG), is a system of geographic grid references, distinct from latitude and longitude, whereby any location in Great Britain can be described in terms of its distance from the origin, which lies to the west of the Isles of Scilly.

<span class="mw-page-title-main">Newlyn</span> Town in Cornwall, England

Newlyn is a seaside town and fishing port in south-west Cornwall, England, United Kingdom. It is the largest fishing port in England.

<span class="mw-page-title-main">Amsterdam Ordnance Datum</span> Vertical datum

Amsterdam Ordnance Datum or Normaal Amsterdams Peil (NAP) is a vertical datum in use in large parts of Western Europe. Originally created for use in the Netherlands, its height was used by Prussia in 1879 for defining Normalnull, and in 1955 by other European countries. In the 1990s, it was used as the reference level for the United European leveling Network (UELN) which in turn led to the European Vertical Reference System (EVRS).

<span class="mw-page-title-main">Tide gauge</span> Device for measuring the change in sea level relative to a datum

A tide gauge is a device for measuring the change in sea level relative to a vertical datum. It is also known as a mareograph, marigraph, and sea-level recorder. When applied to freshwater continental water bodies, the instrument may also be called a limnimeter.

<span class="mw-page-title-main">National Oceanography Centre Southampton</span> Centre for research, teaching, and technology development in Ocean and Earth science

The National Oceanography Centre Southampton (NOCS) is a centre for research, teaching, and technology development in Ocean and Earth science. NOCS was created in 1995, jointly between the University of Southampton and the UK Natural Environment Research Council and is located within the port of Southampton at a purpose-built dockside campus with modern facilities. In 2010 the university and NERC components demerged, and the NERC-managed component became the National Oceanography Centre. The two components of NOCS continue close collaboration through the jointly run Graduate School, shared research facilities and laboratories, complementary research groups, and many joint research grants and publications. The university component “Ocean and Earth Science, National Oceanography Centre Southampton” (OES) is part of the Faculty of Environmental and Life Sciences, (FELS). It was ranked 46th in the world for Earth and Marine Sciences by the QS World University Rankings in 2019.

<span class="mw-page-title-main">Benchmark (surveying)</span> Point with known height used in surveying when levelling

The term benchmark, bench mark, or survey benchmark originates from the chiseled horizontal marks that surveyors made in stone structures, into which an angle iron could be placed to form a "bench" for a leveling rod, thus ensuring that a leveling rod could be accurately repositioned in the same place in the future. These marks were usually indicated with a chiseled arrow – specifically a broad arrow – below the horizontal line. A benchmark is a type of survey marker.

<span class="mw-page-title-main">Chart datum</span> Level of water from which depths displayed on a nautical chart are measured

A chart datum is the water level surface serving as origin of depths displayed on a nautical chart and for reporting and predicting tide heights. A chart datum is generally derived from some tidal phase, in which case it is also known as a tidal datum. Common chart datums are lowest astronomical tide (LAT) and mean lower low water (MLLW). In non-tidal areas, e.g. the Baltic Sea, mean sea level (MSL) is used. A chart datum is a type of vertical datum and must not be confused with the horizontal datum for the chart.

<span class="mw-page-title-main">Ordnance datum</span> Vertical datum used as the basis for deriving altitudes on maps

An ordnance datum (OD) is a vertical datum used by an ordnance survey as the basis for deriving altitudes on maps. A spot height may be expressed as above ordnance datum (AOD). Usually mean sea level (MSL) at a particular place is used for the datum.

Established in 1985, The Global Sea Level Observing System (GLOSS) is an Intergovernmental Oceanographic Commission (IOC) program whose purpose is to measure sea level globally for long-term climate change studies. The program's purpose has changed since the 2004 Indian Ocean earthquake and the program now collects real time measurements of sea level. The project is currently upgrading the over 290 stations it currently runs, so that they can send real time data via satellite to newly set up national tsunami centres. They are also fitting the stations with solar panels so they can continue to operate even if the mains power supply is interrupted by severe weather. The Global Sea Level Observing System does not compete with Deep-ocean Assessment and Reporting of Tsunamis as most GLOSS transducers are located close to land masses while DART's transducers are far out in the ocean.

The Permanent Service for Mean Sea Level is a repository for tide gauge data used in the measurement of long-term sea level change. The PSMSL is based at the National Oceanography Centre in Liverpool, England. It was founded in 1933 as the IUGG Mean Sea Level Committee, and adopted as a Permanent Service of the International Council for Science (ICSU) in 1958.

<span class="mw-page-title-main">Australian Height Datum</span> Vertical datum of Australia

The Australian Height Datum was introduced in 1971 as the official vertical datum for Australia, and thereby serves as the benchmark to which all height measurements are referred. The Australian Height Datum is an amalgamation of decades of spirit levelling work conducted by numerous state and territory authorities across the country, and was corrected to align with the mean sea level observations of thirty tide gauges positioned around the entire coastline. While it remains the published vertical datum for all surveying and engineering operations performed throughout Australia, newer technologies have uncovered numerous deficiencies, offsets and distortions within the Australian Height Datum, leading to discussions about defining a new Australian vertical datum.

<span class="mw-page-title-main">Proudman Oceanographic Laboratory</span>

The former Proudman Oceanographic Laboratory (POL) is based in Brownlow Street, Liverpool, England. In April 2010, POL merged with the National Oceanography Centre, Southampton (NOCS) to form the National Oceanography Centre. The Liverpool laboratory's scientific research focuses on oceanography encompassing global sea-levels and geodesy, numerical modelling of continental shelf seas and coastal sediment processes. This research alongside activities of surveying, monitoring, data management and forecasting provides strategic support for the wider mission of the Natural Environment Research Council.

<span class="mw-page-title-main">National Geodetic Vertical Datum of 1929</span> Vertical datum in the United States

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<span class="mw-page-title-main">North American Vertical Datum of 1988</span> Vertical datum for orthometric heights

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<span class="mw-page-title-main">Vertical datum</span> Reference surface for vertical positions

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<span class="mw-page-title-main">Metres above the Adriatic</span> Vertical datum used in parts of Europe

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<span class="mw-page-title-main">Vertical Offshore Reference Frames</span> UK and Irish hydrographic vertical datum

Vertical Offshore Reference Frames (VORF) is a set of high resolution surface models, published and maintained by the UK Hydrographic Office, which together define a vertical datum for hydrographic surveying and charting in the United Kingdom and Ireland.

References

  1. 1 2 "Newlyn". National Oceanography Centre . Archived from the original on 3 October 2023. Retrieved 3 October 2023.
  2. 1 2 3 Amos, Jonathan (30 April 2021). "The Cornish hut that gave rise to sea level benchmark". BBC . Archived from the original on 3 October 2023. Retrieved 3 October 2023.
  3. 1 2 3 4 5 6 Bradshaw, E.; Woodworth, P.L.; Hibbert, A.; Bradley, L.J.; Pugh, D.T.; Fane, C.; Bingley, R.M. (18 March 2016). "A Century of Sea Level Measurements at Newlyn, Southwest England". Marine Geodesy . 39 (2): 115–140. Bibcode:2016MarGe..39..115B. doi: 10.1080/01490419.2015.1121175 . S2CID   131242174.
  4. "Newlyn Tidal Observatory". Proudman Oceanographic Laboratory . Archived from the original on 14 April 2005.
  5. "NEWLYN". Permanent Service for Mean Sea Level . Archived from the original on 3 October 2023. Retrieved 8 November 2023. Documentation added 1991-06-11 Newlyn 170/161 RLR(1964) is 11.7m below TGBM SW4676 2855
  6. "A Guide to Coordinate Systems in Great Britain" (PDF). Ordnance Survey . pp. 15–16. Archived (PDF) from the original on 24 September 2015. Retrieved 3 October 2023.
  7. 1 2 Manning, Jonathan (25 August 2021). "A century ago, scientists in this remote Cornish hut established height zero. Here's why it matters". National Geographic . Archived from the original on 3 October 2023. Retrieved 3 October 2023. While ODN has proved a priceless reference point for land heights in Britain, it is plays a key role in ocean studies, too
  8. "Station information". Global Sea Level Observing System . Archived from the original on 28 May 2023. Retrieved 3 October 2023. 1915 – 1984 Float/stilling well 1983 – Bubbler gauge
  9. "Newlyn tidal observatory and part of the south pier". Historic England . Archived from the original on 3 October 2023. Retrieved 3 October 2023.
  10. Simons, Paul (1 May 2021). "Newlyn pier plays a crucial role in understanding climate change". The Times . Archived from the original on 3 October 2023. Retrieved 3 October 2023.

Further reading