marégrafos

Marégrafos (also known as mareógrafos) are instruments used to measure and record variations in sea level and tidal fluctuations along coastlines. A marégrafo typically includes a sensor located at or near the shoreline, a stilling well or protected chamber to cushion the mechanism, and a recording device on land that traces water level over time. The data are usually expressed relative to a fixed vertical datum, such as mean sea level at the station.

Historically, mareógrafos relied on a float attached to a recording pen inside a tube that protected the mechanism (stilling well). With advances in technology, many stations now use electronic pressure transducers, acoustic or radar level sensors, enabling continuous automatic recordings with higher precision and longer service life in harsh environments.

Marégrafos serve multiple purposes: monitoring tides and sea level variations, establishing local benchmarks, and contributing to longer-term records of mean sea level and sea-level rise. They are essential for coastal management, navigation safety, and climate studies. Data from marégrafos are often compiled by national hydrographic services and international networks, and are coordinated in archives such as the Permanent Service for Mean Sea Level (PSMSL) and other regional data centers.

Modern installations may integrate GPS for vertical datum control, provide real-time data feeds, and support quality control through metadata, calibration records, and explicit datum definitions. See also tide gauge, sea level rise, and oceanography.