Publication Date:
2019-03-27
Description:
The first in situ measurements of seawater density that referred to a geographical position at sea and time of the year were carried out by Count Luigi Ferdinando Marsili between 1679 and 1680 in the Adriatic Sea, Aegean Sea, Marmara Sea, and the Bosporus. Not only was this the first investigation with documented oceanographic measurements carried out at stations, but themeasurements were described in such an accurateway that the authorswere able to reconstruct the observations in modern units. These first measurements concern the ‘‘specific gravity’’ of seawaters (i.e., the ratio between fluid densities). The data reported in the historical oceanographic treatise
Osservazioni intorno al Bosforo Tracio (Marsili) allowed the reconstruction of the seawater density at different
geographic locations between 1679 and 1680. Marsili’s experimental methodology included the collection of surface
and deep water samples, the analysis of the samples with a hydrostatic ampoule, and the use of a reference water to
standardize the measurements.Acomparison of reconstructed densities with present-day values shows an agreement
within 10%–20% uncertainty, owing to various aspects of the measurement methodology that are difficult to reconstruct
from the documentary evidence. Marsili also measured the current speed and the depth of the current
inversion in the Bosporus, which are consistent with the present-day knowledge. The experimental data collected in
the Bosporus enabledMarsili to enunciate a theory on the cause of the two-layer flow at the strait, demonstrated by
his laboratory experiment and later confirmed by many analytical and numerical studies.
Description:
American Meteorological Society.
Description:
Published
Description:
845 - 860
Description:
4A. Oceanografia e clima
Description:
JCR Journal
Keywords:
Ocean
;
Density currents
;
Measurements
;
Ship observations
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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