Mapping Diamondiferous Gravel

Using the Aquares Resistivity System on a Fluvial Diamond Concession
An Aquares resistivity survey was carried out in a river in sub-Saharan Africa to map the sub-bottom features of a diamond concession. Diamondiferous gravels were distinguished remotely from bedrock and other soft sediments by the Aquares Resistivity System (ARS), a sub-bottom acquisition and profiling tool. It was selected due to its cost-effective operation and ability to provide qualitative and quantitative results. The ARS utilises recently developed processing innovations, which enable data to be presented in vertical sections and horizontal slices. This facilitates accurate volume calculations and the development of isopach maps for distinguishable types of bedrock and sediments. Acoustic sub-bottomprofiling... (read more)
2009-06-04 12:00:00

K.U.M. and the SEA-SEIS Ocean-bottom Seismometer Deployment Mission

Capturing the Earth’s Heartbeat
Scientists from the Dublin Institute for Advanced Studies (DIAS) have undertaken a 21-day marine science mission, deploying 18 ocean-bottom seismometers (OBSs) at a series of locations on the floor of the North Atlantic Ocean. The OBSs function as sensors and are to record the tiny vibrations of the Earth caused by seismic waves, generated by earthquakes and ocean waves, and will record these vibrations for the next 18 months. The intended outcome of this mission is to collect data that will enable the DIAS scientists to better understand the activity under and on the ocean floor along Ireland’s west coast,... (read more)
2018-12-11 11:38:02

Technology in Focus: Acoustic Doppler Current Profilers (ADCP)

Widespread Applications Stem from Diverse Measurement Capabilities
Rather than a spinning propeller, the Acoustic Doppler Current Profiler (ADCP) – just like dolphins and bats – uses sound to explore its environment. Operating underwater, the method works like hand-held radars used by police to catch speeding motorists. This article explains the technique of this frequently used type of instrument and some of its applications. A sound burst is emitted by the ADCP along beams angled downward. Echoes are returned due to scattering off particles carried by water currents. A second burst can be used to track movement over the seabed. By analysing these sound echoes, the ADCP makes... (read more)
2017-01-25 08:53:33

Visited for You

  Ocean Business   From 31 March to 2 April, Ocean Business and Ocean Careers took centre stage at the National Oceanography Centre in Southampton (UK), followed by Offshore Survey from 1 April.   However, on 30 March there was already much ongoing activity; stands were set up, delegates arrived. Hydro international was invited to join RESON, before the opening of the show, to see the RESON sonars in action. Surveying the harbour of Southampton on board of Southampton's Port Management Protector, a few remarkable features were discovered that even the regular harbour surveyors had not discovered before! In a... (read more)
2009-05-12 12:00:00

'As it Was'

by the Old Hydrographer
Matthew Fontaine Maury is probably the best known of all hydrographers, and the most celebrated both in his homeland, the United States of America, and in Europe. He served for 18 years as Superintendent of the Depot of Charts and Instruments in Washington during which time he made his name with the publication of his Wind and Weather Charts and Sailing Directions, his bathymetric chart of the North Atlantic and his book 'The Physical Geography of the Sea'. Two Huguenot families, who had fled from France after the Revocation of the Edict of Nantes in 1685, had come together in... (read more)
2008-01-01 01:00:00

Deepsea Positioning Accuracy

First NEMO Tower for Astrophysical Research
The Italian Istituto Nazionale di Fisica Nucleare (INFN) is developing a large underwater apparatus to investigate new frontiers in astrophysical research. The NEutrino Mediterranean Observatory, NEMO, consists of a 3D-array of optical sensors capable of detecting the primary source of extremely high-energy neutrinos. This article covers underwater positioning techniques: system architecture, technical, advanced and data processing aspects, and preliminary data analysis. The first prototype, NEMO Phase 1, was deployed in December 2006 off the coast of Catania. A set of synchronous acoustic beacons was installed in the sea at a depth of 2,000m to position a large number of optical... (read more)
2007-05-31 12:00:00

New Technology Rewrites History

Unravelling the mystery of the U-166
In early 2001, BP Exploration and Production, and Shell International and Production contracted C&C Technologies Inc. to conduct a marine survey for the proposed Okeanos Gas Pipeline route, using their new HUGIN 3000 AUV. This state-of- the-art deep-water survey vehicle utilises a full array of survey instruments to survey faster and more accurately than can conventional deep-tow survey systems. Through the use of this new technology a startling discovery was made that has helped unravel an intriguing historical mystery in the Gulf of Mexico. The sinking of the Norlindo by U-507 in May 1942 led to a wave of destruction... (read more)
2008-01-01 01:00:00

Surveying Japanese Inland and Coastal Waters

Technical Records Set for Lidar Penetration
In March 2015, Leica Geosystems conducted a series of demonstration surveys in Japan with the HawkEye III Airborne Topographic Bathymetric Lidar system. This demonstration was designed to prove the depth performance and general capabilities of the HawkEye III system in Japanese waters. It ambitiously targeted 13 geographically separated areas ranging from land-locked rivers, coastal estuaries and coastal strips to offshore islands and coral reefs. The HawkEye III successfully demonstrated its capabilities, collecting seamless datasets in diverse coastal and river environments as well as setting new records for depth penetration for both the HawkEye III deep sensor and the Chiroptera II shallow... (read more)
2016-04-04 10:16:39

No More Spatial ­Misinterpretation Using Different Technologies

Capturing an Entire Maltese Islands’ Territory
Malta, the smallest European Union state, has carried out a country-wide hydrographic survey which was initiated in Q1 2012 and completed in Q4 of the same year. Aimed at acquiring baseline information that satisfies a number of key National and European Directives including the Water Framework Directive, the central Mediterranean state took the ambitious step of employing different technologies within one project in order to ensure compliance. An inability to collect base physical data on which to build reliable thematic environmental data would not only make Malta more exposed to various environmental pressures due to poorly informed policy decisions, but... (read more)
2013-01-18 02:49:01

The Order of Canada

Interview with Mike Eaton, CHS Hydrographer and Mariner (Rtd)
There were three major overlapping phases in Mike Eaton’s career: Arctic developments in the Canadian Hydrographic Service, positioning systems development while at the Bedford Institute and electronic chart development after his retirement. In the Arctic he found ways to acoustically measure the depth beneath the ice and developed a rather hairy towfish sounding method from a helicopter in open waters. At the Bedford Institute he worked with Paul Brunavs and Dave Gray on the propagation of the radio ground waves used by Decca, Loran-C etc. Later he became deeply involved in the initial specifications of the electronic chart, and was... (read more)
2008-01-01 01:00:00
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