:Newlyn Tidal Observatory

{{Infobox historic site

| name = Newlyn Tidal Observatory

| native_name =

| native_language =

| other_name = GLOSS ID 241

| image = Newlyn harbour light 342.jpg

| caption = View of Newlyn Harbour with the lighthouse and Tidal Observatory to its right

| type = Tide gauge

| locmapin = Cornwall

| coordinates = {{coord|50.103000|-5.542806}}

| location = Newlyn, Cornwall, England

| area =

| built = 1915

| architect =

| architecture =

| governing_body =

| owner = National Oceanography Centre{{cite web |title=Newlyn |url=https://psmsl.org/data/obtaining/stations/202.php |website=National Oceanography Centre |access-date=3 October 2023 |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003203237/https://psmsl.org/data/obtaining/stations/202.php |url-status=live}}

| website = {{official_URL}}

| designation1 = Grade II

| designation1_offname = Newlyn tidal observatory and part of the south pier

| designation1_date = 11 December 2018

| designation1_number = {{listed building England|1460225}}

}}

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.

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. Inside the building is an Ordnance Survey benchmark, constituted of a brass bolt (OSBM SW 4676 2855), and a {{convert|1.6|m|adj=on}} diameter stilling well set into the pier which has ocean access via an inlet.{{cite web |title=Newlyn Tidal Observatory |url=http://www.pol.ac.uk/ntslf/tgi/ntobs.html |website=Proudman Oceanographic Laboratory |archive-url=https://web.archive.org/web/20050414145457/http://www.pol.ac.uk/ntslf/tgi/ntobs.html |archive-date=14 April 2005}}{{cite web |title=NEWLYN |url=https://psmsl.org/data/obtaining/stations/202.php |website=Permanent Service for Mean Sea Level |access-date=8 November 2023 |quote=Documentation added 1991-06-11 Newlyn 170/161 RLR(1964) is 11.7m below TGBM SW4676 2855 |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003203237/https://psmsl.org/data/obtaining/stations/202.php |url-status=live}}

History

{{Annotated image

| image = Newlyn South Pier Light (7342).jpg

| image-width = 1000

| image-left = -200

| image-top = -175

| width = 250

| height = 175

| float = left

| annotations =

| caption = 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 {{cvt|4.751|m}} 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.{{cite news |last1=Amos |first1=Jonathan |title=The Cornish hut that gave rise to sea level benchmark |url=https://www.bbc.co.uk/news/science-environment-56935097 |access-date=3 October 2023 |work=BBC |date=30 April 2021 |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003203242/https://www.bbc.co.uk/news/science-environment-56935097 |url-status=live}}{{cite journal |title=A Century of Sea Level Measurements at Newlyn, Southwest England |journal=Marine Geodesy |date=18 March 2016 |doi=10.1080/01490419.2015.1121175 |last1=Bradshaw |first1=E. |last2=Woodworth |first2=P.L. |last3=Hibbert |first3=A. |last4=Bradley |first4=L.J. |last5=Pugh |first5=D.T. |last6=Fane |first6=C. |last7=Bingley |first7=R.M. |volume=39 |issue=2 |pages=115–140 |bibcode=2016MarGe..39..115B |s2cid=131242174 |doi-access=free}}{{cite web |title=A Guide to Coordinate Systems in Great Britain |url=https://www.ordnancesurvey.co.uk/documents/resources/guide-coordinate-systems-great-britain.pdf |website=Ordnance Survey |access-date=3 October 2023 |pages=15–16 |archive-date=24 September 2015 |archive-url=https://web.archive.org/web/20150924061607/http://www.ordnancesurvey.co.uk/docs/support/guide-coordinate-systems-great-britain.pdf |url-status=live}}

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.{{cite web |title=Station information |url=https://gloss-sealevel.org/gloss-station-handbook |website=Global Sea Level Observing System |quote=1915 – 1984 Float/stilling well 1983 – Bubbler gauge |access-date=3 October 2023 |archive-date=28 May 2023 |archive-url=https://web.archive.org/web/20230528233912/https://gloss-sealevel.org/gloss-station-handbook |url-status=live}}

The Ordnance Survey operated the tide gauge until 1983, when the Natural Environment Research Council took over the management. The observatory was designated as grade II listed status by Historic England in December 2018.{{cite web |title=Newlyn tidal observatory and part of the south pier |url=https://historicengland.org.uk/listing/the-list/list-entry/1460225 |website=Historic England |access-date=3 October 2023 |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003203242/https://historicengland.org.uk/listing/the-list/list-entry/1460225 |url-status=live}} As of 2023 the observatory is operated by the National Oceanography Centre, and funding support is contributed by the UK Environment Agency.

Impact

File:Newlyn Monthly Mean Sea Level 1915 - 2023 (m).png

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.

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", and in 2021 the impact of the data on ocean and climate change studies was noted.{{cite news |last1=Manning |first1=Jonathan |title=A century ago, scientists in this remote Cornish hut established height zero. Here's why it matters. |url=https://www.nationalgeographic.co.uk/science-and-technology/2021/08/a-century-ago-scientists-in-this-remote-cornish-hut-established-height-zero-heres-why-it-matters |access-date=3 October 2023 |work=National Geographic |date=25 August 2021 |quote=While ODN has proved a priceless reference point for land heights in Britain, it is plays a key role in ocean studies, too |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003203242/https://www.nationalgeographic.co.uk/science-and-technology/2021/08/a-century-ago-scientists-in-this-remote-cornish-hut-established-height-zero-heres-why-it-matters |url-status=live}}{{cite news |last1=Simons |first1=Paul |title=Newlyn pier plays a crucial role in understanding climate change |url=https://www.thetimes.com/uk/article/weather-eye-sat-1-may-tqvjfhr7h |work=The Times |date=1 May 2021 |access-date=3 October 2023 |archive-date=3 October 2023 |archive-url=https://web.archive.org/web/20231003205434/https://www.thetimes.co.uk/article/weather-eye-sat-1-may-tqvjfhr7h |url-status=live}}

:Newlyn Tidal Observatory

Building and location

History

Impact

See also

References

Further reading