{ "@context": "https://schema.org", "@type": "Dataset", "@id": "http://portal.medin.org.uk/portal/json-ld/3c5785dbad235061b42a446c977c290c.jsonld", "identifier": "3c5785dbad235061b42a446c977c290c", "url": "http://portal.medin.org.uk/portal/?details&tpc=3c5785dbad235061b42a446c977c290c", "name": "Wave statistics from Acajutla, El Salvador", "description": "The data set comprises wave height and period statistics, and sea level measurements collected near Acajutla, El Salvador. Accurate positions are not known and the location of both instruments is approximated as 13 deg 32.0 N, 89 deg 57.0 W. There is no other information available regarding these sites. The data were collected between 1 December 1974 and 30 November 1975 using an Institute of Oceanographic Sciences (IOS) frequency modulated (FM) pressure recorder deployed in the harbour at Acajutla and a waverider buoy deployed offshore from the harbour. The IOS FM pressure recorder uses a pressure sensitive diaphragm to vary the gap of a parallel plate capacitor, resulting in a frequency modulation of a nominal 100 KHz carrier signal. This signal is recorded on a shore-based magnetic tape data logger linked to the pressure unit by armoured cable. Data were recorded for ten minutes every three hours and analysed later as described by Hardcastle (1978). Some uncertainty surrounds the ability of the pressure recorder to respond accurately to the surface waves since the transfer function from pressure to surface wave height is incompletely understood. Draper (1957) has derived a factor to correct for the hydrodynamic attenuation of the pressure signal. This factor varies with mean zero up-crossing period and may increase wave heights by up to 15 percent compared with classical wave theory (Fortnum and Hardcastle, 1979). This data set has not been corrected. The waverider buoy generates a heave signal via an internal accelerometer to an accuracy of better than five percent. This signal is used to amplitude modulate a 27-30 MHz radio signal which is transmitted continuously and can be received by the recording device at a range of up to 50 km depending on local conditions (Driver, 1980). The data were collected by Livesey and Henderson (now incorporated with Binnie and Partners, 65 London Rd., Redhill, Surrey, RH1 1LG, UK) and are stored at the British Oceanographic Data Centre.", "includedInDataCatalog": { "@id": "http://portal.medin.org.uk/portal/json-ld/catalog.jsonld" }, "conditionsOfAccess": [ "Usage restrictions are specified in the terms of the licence", "restricted: Data are freely available for use in teaching and research, providing due acknowledgment in any publication produced, following agreement to the terms and conditions of the British Oceanographic Data Centre Data Licence. The licence terms and conditions are available via https://www.bodc.ac.uk/data/documents/nodb/267795/" ], "temporalCoverage": "1974/1975", "keywords": [ { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/N01/current/NDGO0003/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/N01/current/", "termCode": "NDGO0003", "name": "Natural Environment Research Council Designated Data Centres" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/N01/current/NDGO0001/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/N01/current/", "termCode": "NDGO0001", "name": "Marine Environmental Data and Information Network" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/L13/current/UK/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/L13/current/", "termCode": "UK", "name": "unknown" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/ASLV/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P02/current/", "termCode": "ASLV", "name": "Sea level" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/P02/current/WVST/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P02/current/", "termCode": "WVST", "name": "Wave height and period statistics" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/P22/current/10/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P22/current/", "termCode": "10", "name": "Elevation" }, { "@type": "DefinedTerm", "identifier": "http://vocab.nerc.ac.uk/collection/P22/current/28/", "inDefinedTermSet": "http://vocab.nerc.ac.uk/collection/P22/current/", "termCode": "28", "name": "Oceanographic geographical features" } ], "spatialCoverage": { "@type": "Place", "geo": { "@type": "GeoShape", "box": "13 -90 14 -89" }, "additionalProperty": [ { "@type": "PropertyValue", "propertyID": "http://www.opengis.net/def/crs/OGC/1.3/CRS84", "value": "urn:ogc:def:crs:EPSG:4326" } ] }, "maintainer": [ { "@type": "Organization", "name": "British Oceanographic Data Centre", "description": "custodian", "email": "enquiries@bodc.ac.uk", "address": { "@type": "PostalAddress", "streetAddress": "Joseph Proudman Building, 6 Brownlow Street", "postalCode": "L3 5DA", "addressLocality": "Liverpool", "addressRegion": "Merseyside", "addressCountry": "United Kingdom" } } ], "producer": [ { "@type": "Organization", "name": "Livesey & Henderson", "description": "originator", "email": "inapplicable", "address": { "@type": "PostalAddress", "streetAddress": "Albury House, Albury", "addressLocality": "Guildford", "addressRegion": "Surrey", "addressCountry": "United Kingdom" } } ], "publisher": [ { "@type": "Organization", "name": "British Oceanographic Data Centre", "description": "pointOfContact", "email": "enquiries@bodc.ac.uk", "address": { "@type": "PostalAddress", "streetAddress": "Joseph Proudman Building, 6 Brownlow Street", "postalCode": "L3 5DA", "addressLocality": "Liverpool", "addressRegion": "Merseyside", "addressCountry": "United Kingdom" } } ], "provider": [ { "@type": "Organization", "name": "British Oceanographic Data Centre", "description": "distributor", "email": "enquiries@bodc.ac.uk", "address": { "@type": "PostalAddress", "streetAddress": "Joseph Proudman Building, 6 Brownlow Street", "postalCode": "L3 5DA", "addressLocality": "Liverpool", "addressRegion": "Merseyside", "addressCountry": "United Kingdom" } } ], "creator": [ { "@type": "Organization", "name": "Livesey & Henderson", "description": "originator", "email": "inapplicable", "address": { "@type": "PostalAddress", "streetAddress": "Albury House, Albury", "addressLocality": "Guildford", "addressRegion": "Surrey", "addressCountry": "United Kingdom" } } ], "sdPublisher": { "@type": "Organization", "url": "https://portal.medin.org.uk/portal/", "name": "Marine Environmental Data and Information Network (MEDIN)", "description": "The MEDIN portal contains information about 19493 marine datasets from over 600 UK organisations. Metadata are an enduring resource and contact details are publicly available for a long time. \r\n\t\tPlease contact us (enquiries@medin.org.uk) if you find your contact details on the MEDIN portal and do not consent to this. \r\n\t\tYou can now use our GitHub repository to report issues or access related documents. Metadata records are updated daily and were last updated 2026-04-19. Record deletion takes place weekly and the latest occurred 2026-04-12." } }