How do we measure the Maracaibo coastal currents?

1. Where is Maracaibo?

Maracaibo, in northwestern Venezuela, is a city of immense geographical significance. It is situated on the shores of Lake Maracaibo, the largest lake in South America. The lake is connected with the Caribbean Sea by a strait, which is one of the great sea routes of navigation and a water exchange route between the lake and the sea. The superior local topography, with mountains constituting three sides of a lake basin, creates a unique local microclimate in addition to dominating local oceanography and hydrology.

Sheer centuries of the best in local history set this city apart. Locals have traditionally lived originally along with natives living there originally as well as locals visually influenced by the art, culture, as well as mode of living through natives. The colonizers were succeeded by the Spanish colonizers, and Maracaibo emerged as a major hub of trade and agriculture. Maracaibo is presently a prosperous city with a robust economy based on the oil industry. The region is among the world's largest producing areas of oil, and oil rigs spread across the shores of Lake Maracaibo.

The natural environment surrounding Maracaibo is one of high diversification and fertility. Mangrove swamp lines the shores of the lake and the strait and maintains an extremely important aquatic and land animal life system. Mangroves help act as a natural barrier to beach erosion and maintain the ecological balance of the region.

2. What are the coastal currents surrounding Maracaibo?

Maracaibo ocean currents are governed by a complex interaction of numerous variables. One control factor is exchange between Lake Maracaibo and the Caribbean Sea through the strait. Sea and lake fluctuations of sea level, temperature, and salinity produce a flow of water through the strait. In periods of wet weather over the lake basin, huge quantities of freshwater are released to the sea and impact the transport and density of the coastal waters.

The Caribbean Sea also experiences tides. The semi-diurnal and diurnal tidal phases produce water-level fluctuations at the strait mouth, which affect the water exchange moving in and out of the lake. Dominant winds in the region, being essentially the northeasterly trade winds, push surface water to the west. This current of wind is mixed with the water flux from the strait as well as tidal currents to create a complex pattern of water flow.

The bottom and bathymetry of the strait as well as the lake bottom exert strong control on coastal currents. The underwater topography such as sandbars, reefs, and channels may either dissipate or guide the flow of the currents and thus produce complex flow patterns. Oil platforms as well as other man - made structures within the lake and strait can influence the flow of the currents as well.

3. Maracaibo coastal water flow measurement

Surface Drifting Buoy Method

Surface drifting buoy method is an old method used to measure coastal water flow. Researchers release buoys equipped with tracking devices into the sea. Following the drift of these buoys periodically, they discover the direction and speed of surface currents. This method also has certain disadvantages. It provides data only for the surface level of the water column, and buoys are highly influenced by wind. The wind can force the buoys towards a path other than the true direction of the underlying currents.

Moored Ship Method

The moored ship method uses a stationary ship as a platform to measure currents. Equipment is dropped from the ship to measure water flow at various depths. While it is theoretically possible to acquire detailed vertical current profiles with this method, there are certain drawbacks. The spatial coverage is limited to the surrounding environment of the moored ship, and the ship will disturb the natural flow of the water and hence affect the accuracy of the measurements. In addition, it can be expensive and logistically troublesome to tie up a ship for long periods of time.

Acoustic Doppler Current Profiler (ADCP) Method

ADCP is a more advanced and efficient technique for measuring coastal currents. ADCPs can detect currents in the water over a wide vertical range, providing detailed information on the velocity structure of the water column. ADCPs may be mounted on a wide variety of platforms, from ships and buoys to the seafloor. Ship- mounted ADCPs can collect information continuously as the ship moves along, covering extensive ground in a short period of time. Bottom- mounted ADCPs can obtain long- term, fixed - point measurements and allow scientists to study long - term coastal current patterns.

4. How do Doppler principle- based ADCPs work?

ADCPs operate on the Doppler principle. They transmit acoustic signals into the water. The signals bounce off suspended particles such as sediment, plankton, or bubbles in the water. If the water is in motion, the frequency of the reflected signals is changed. By measuring this change in frequency, the ADCP can calculate the velocity of the water relative to the instrument.

Most ADCPs have several transducer beams, which are typically four or more, directed in different directions, respectively. The multiple - beam configuration enables the determination of the three - dimensional water velocity. Through the summation of the signals from the beams, the ADCP can create a full view of the current velocity at different depths in the water column. The data collected by the ADCP can be processed in real-time or stored for later analysis, providing valuable information on the dynamics of the coastal currents.

5. What is needed for high-quality measurement of Maracaibo coastal currents?

For the high-quality measurement of Maracaibo's coastal currents, the measuring instrument should possess some crucial characteristics. It should be made of robust material, compact size, lightweight, minimal power consumption, and minimal cost. With these specifications, it is possible to deploy many instruments in order to provide complete spatial coverage.

ADCPs with titanium alloy casings are highly recommended. Titanium alloy is highly resistant to corrosion, which is crucial for use in the adverse seawater environment on a long-term basis. The alloy is resistant to the corrosion effect of sea saltwater to prevent damage from occurring on the internal components of the ADCP. Titanium alloy also has strength, with low weight, guaranteeing ruggedness and handlability to the instrument. These attributes enable effective and sustainable measurement of currents surrounding the Maracaibo coastal area.

6. How to choose the suitable equipment for current measurement?

Usage-Based Choice

ADCP selection is done based on its usage. In the case of ship-borne measurement, ship-mounted ADCPs are ideal. They can provide real-time observations as the ship moves in the water, traversing a large extent in a comparatively short time. For fixed - point long - term observation, bottom - mounted ADCPs are more suitable. They can provide continuous data over a long period, and researchers can study long - term coastal current patterns. Floating ADCPs are more suitable to track the path of water masses over a large area and provide valuable information on large - scale circulation patterns.

Depth Selection

The frequency of ADCP should also be established based on the water depth. For less than 70m depths, 600kHz ADCPs can be used. They are capable of providing high-resolution measurement in shallow waters. For a maximum depth of 110m, 300kHz ADCPs can be used. For greater depth, up to 1000m, 75kHz ADCPs can be used.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, for those who are on a tight budget,the ADCP supplier China Sonar's PandaADCP is highly recommended. Made of pure titanium alloy, it is well known for its excellent performance while being very cheap. It is the ideal choice for those who are on a tight budget but still want quality ADCPs for coastal current measurements. You can find more information about them on their official website: https://china-sonar.com/.

Here is a table with some well known ADCP instrument brands and models.