© OpenStreetMap contributors
- Add External Layer
- Upload Shapefile
- Close
Use the checkbox () to show or hide a layer.
Use the radio buttons () to select a layer to use with the identify function.
- Layers
- Opacity
Available layers
Search for marine data across UK organisations
- How-To
- About
- Contact MEDIN
- Share
Metadata: Wave statistics from Acajutla, El Salvador
Abstract:
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.
Data holder:
British Oceanographic Data Centre
Use constraints:
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/
Other details | ||
Internal code | Internally assigned metadata identifier | 1633 |
Title | The title is used to provide a brief and precise description of the dataset such as 'Date', 'Originating organisation/programme', 'Location' and 'Type of survey'. All acronyms and abbreviations should be reproduced in full. | Wave statistics from Acajutla, El Salvador |
Alternative title | The purpose of alternative title is to record any additional names by which the dataset may be known. | British Oceanographic Data Centre record 1048ACAJUTLA |
File Identifier | The File Identifier is a code, preferably a GUID, that is globally unique and remains with the same metadata record even if the record is edited or transferred between portals or tools. | 3c5785dbad235061b42a446c977c290c |
Resource Identifier | This is the code assigned by the data owner. | EDMED4290 |
Resource type | The resource type will likely be a dataset but could also be a series (collection of datasets with a common specification) or a service. | dataset |
Start date | This describes the date the resource starts. This may only be the year if month and day are not known | 1974 |
End date | This describes the date the resource ends. This may only be the year if month and day are not known | 1975 |
Spatial resolution | This describes the spatial resolution of the dataset or the spatial limitations of the service. | inapplicable |
Frequency of updates | This describes the frequency with which the resource is modified or updated i.e. a monitoring programme that samples once per year has a frequency that is described as 'annually'. | asNeeded |
Abstract | The abstract provides a clear and brief statement of the content of the resource. | 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. |
Lineage | Lineage includes the background information, history of the sources of data, data quality statements and methods. | This dataset was created by the organisations with the "originator" role in this metadata record following their in-house data processing and quality control procedures. The data were then provided to the British Oceanographic Data Centre (BODC) for ingestion into one of the schemas of the National Oceanographic Database (NODB). During ingestion BODC undertake quality control, documentation and metadata enhancement procedures appropriate to the type of data. For an overview please see http://www.bodc.ac.uk/about/informationtechnology/dataprocessing_steps/. BODC supply full information about data collection, data processing and data quality with all data requests to enable users to assess data suitability themselves. Instrument(s) used to collect data: wave recorders; sea level recorders. |
Additional information | This describes relevant references to the data e.g. reports, articles, websites plus other useful information not captured elsewhere. | Publication year: 1957-01-01 Publication title: Attenuation of sea waves with depth Publication authors: L. Draper Publication editors: La Houille Blanche, 12 Publication year: 1979-01-01 Publication title: Waves recorded at Aldeburgh, Dunwich and Southwold on the east coast of England Publication authors: B.C.H. Fortnum & P.J. Hardcastle Publication editors: Institute of Oceanographic Sciences, Report No. 65 Publication year: 1978-01-01 Publication title: Sea wave recording system using magnetic tape cassettes Publication authors: P.J. Hardcastle Publication editors: Institute of Oceanographic Sciences, Report No. 61 Publication year: 1980-01-01 Publication title: A guide to sea wave recording Publication authors: J.S. Driver Publication editors: Institute of Oceanographic Sciences, Report No. 103 |
Related keywords | ||
Keyword | General subject area(s) associated with the resource, uses multiple controlled vocabularies | Natural Environment Research Council Designated Data Centres |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Marine Environmental Data and Information Network | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | unknown | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Sea level | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Wave height and period statistics | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Elevation | |
General subject area(s) associated with the resource, uses multiple controlled vocabularies | Oceanographic geographical features | |
Geographical coverage | ||
North | The northern-most limit of the data resource in decimal degrees | 14 |
East | The eastern-most limit of the data resource in decimal degrees | -89 |
South | The southern-most limit of the data resource in decimal degrees | 13 |
West | The western-most limit of the data resource in decimal degrees | -90 |
Responsible organisations | ||
Role | The point of contact is person or organisation with responsibility for the creation and maintenance of the metadata for the resource. | pointOfContact |
Organisation name | British Oceanographic Data Centre | |
Individual name | Polly HadÅžiabdic | |
Position name | Head of the BODC Requests Team | |
Delivery point | Joseph Proudman Building, 6 Brownlow Street | |
Postal code | L3 5DA | |
City | Liverpool | |
Administrative area | Merseyside | |
Country | United Kingdom | |
URL | http://www.bodc.ac.uk/ | |
Role | The distributor is the person or organisation that distributes the resource. | distributor |
Organisation name | British Oceanographic Data Centre | |
Position name | Director | |
Delivery point | Joseph Proudman Building, 6 Brownlow Street | |
Postal code | L3 5DA | |
City | Liverpool | |
Administrative area | Merseyside | |
Country | United Kingdom | |
URL | http://www.bodc.ac.uk/ | |
Role | The originator is the person or organisation who created, collected or produced the resource. | originator |
Organisation name | Livesey & Henderson | |
Individual name | Unknown | |
Position name | Unknown | |
Delivery point | Albury House, Albury | |
City | Guildford | |
Administrative area | Surrey | |
Country | United Kingdom | |
Role | The custodian is the person or organisation that accepts responsibility for the resource and ensures appropriate care and maintenance. If a dataset has been lodged with a Data Archive Centre for maintenance then this organisation is be entered here. | custodian |
Organisation name | British Oceanographic Data Centre | |
Position name | Director | |
Delivery point | Joseph Proudman Building, 6 Brownlow Street | |
Postal code | L3 5DA | |
City | Liverpool | |
Administrative area | Merseyside | |
Country | United Kingdom | |
URL | http://www.bodc.ac.uk/ | |
Resource locators | ||
Locator URL | Web address (URL) that links to the resource | https://www.bodc.ac.uk/data/bodc_database/nodb/ |
Locator name | Name of the web resource | BODC online data delivery service |
Locator function | Code that describes the function of the resource. ISO function code chosen from ISO 19115-1 Codelist | order |
Dataset constraints | ||
20 Limitations on Public Access - Access constraints | restricted | |
20 Limitations on Public Access - Other constraints | This states any limitations on access to the data and uses free text. | 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/ |
21 Conditions for Access and Use - Use limitation | This states any constraints on use of the data. Multiple conditions can be recorded for different parts of the data resource. If no conditions apply, then `No condtions apply` is recorded. This uses free text. | Usage restrictions are specified in the terms of the licence |
Version info | ||
Date of publication | The publication date of the resource or if previously unpublished the date that the resource was made publicly available via the MEDIN network. | 2017-10-03 |
Date of last revision | The most recent date that the resource was revised. | 2017-01-30 |
Date of creation | The date that the resource was created. | 2010-10-19 |
Harvest date | The date which this record has been (re)harvested from the provider. | 2024-04-21 |
Metadata date | The date when the content of this metadata record was last updated. | 2018-02-06 |
Metadata standard name | The name of the metadata standard used to create this metadata | MEDIN Discovery Metadata Standard |
Metadata standard version | The version of the MEDIN Discovery Metadata Standard used to create the metadata record | Version 2.3.8 |