How do we measure the Myrtle Beach coastal currents?

1. Where is Myrtle Beach?

Myrtle Beach, a vibrant beach gem, is located on the Grand Strand in northeast South Carolina, USA. Covering over 60 miles of shoreline, the area is a popular tourist destination for its beautiful beaches, good weather, and many recreational activities. The beach itself is made up of gentle, sandy shores that incline very gradually into the Atlantic Ocean.

It is not just beaches that the area comprises; there is also an extensive network of waterways. West of the coast, Intracoastal Waterway runs parallel to the shore. The waterway is an important route for shipping and boating from port to marina along the coast. It is an active system where river freshwater from neighboring rivers mixes with ocean water to create an abnormal habitat for diverse marine species. The Intracoastal Waterway is lined with marshes that have salt-resistant plants like pickleweed and cordgrass. The marshes serve as nurseries for numerous thousands of fish, crab, and shrimp species and a secure habitat and good food supply.

Myrtle Beach is a vibrant, family-friendly setting. The community is filled with an assortment of resorts, hotels, restaurants, and entertainment complexes. The Myrtle Beach Boardwalk, popular due to its title, is the hub, surrounded by amusement parks, arcades, and souvenir shops. Tourism drives the economy, as millions of visitors arrive in the area annually to enjoy the sun, sea, and sand.

2. What are the coastal currents off Myrtle Beach?

Myrtle Beach coastal currents are controlled by numerous factors. Tides are a fundamental force. The area experiences semi - diurnal tides, two high and two low tides daily. During flood tides, ocean water flows toward the beach and into the Intracoastal Waterway. This tide carries nutrients from the open sea that are critical to the growth of marine organisms in estuarine environments. During the outgo of the tide, water moves back into the ocean along with sediment and organic material from the estuaries. The tidal range is unequal, larger in the case of spring tides when sun gravitation pull and moon gravitation pull act in the same direction and smaller in the case of neap tides when both the gravitations act in the opposite direction.

The wind patterns control the coastal currents to a great extent. The southeasterly winds are experienced in summer. The southeasterly winds push the surface waters towards the land and thus create onshore currents. These onshore currents have the capability of increasing productivity of the shore system by introducing warmer, enriched water. They also contribute to the formation of surf breaks that are preferred by surfers. Northern winds dominate during winter. Surface waters are forced off-shore by these winds, leading to currents off-shore. Wind-generated currents also cause stirring of the water column, aerating deeper water and dispersing nutrients throughout the coast.

The shape of the coast and seafloor topography also affect the pattern of the currents. The slope of the beach, if gently sloping, and the presence of sandbars and shoals near the coast can slow down or deflect the flow of the water. Coastal inlets, such as the Little River Inlet and the Murrells inlet, can obstruct the flow of water and generate stronger currents within the area. The bathymetry of the seafloor, which is complex with varying depths and underwater features, influences the movement of the coastal currents.

3. How to observe the coastal water flow of Myrtle Beach?

They are able to observe the flow of coastal water along Myrtle Beach with the help of surface drift buoys. They are small, floating units of equipment equipped with GPS tracking systems. Once placed on the water, the surface currents push them around. Monitoring the movement of these buoys over a span of time enables scientists to estimate the velocity and direction of the surface-level currents. But this technique gives data only for the upper few meters of the water column, and it could be influenced by wind - driven surface waves.

The second technique is the employment of moored current meters. These are tied to the ocean floor or Intracoastal Waterway bottom at particular points in the vicinity of Myrtle Beach. They are capable of measuring the velocity and direction of the currents at various depths. Current meters moored down, when suitably placed, can yield continuous data records over long periods and are beneficial to ascertain the vertical structure of currents. However, they are limited to the location where they are moored, and installation and maintenance require labor.

Acoustic Doppler Current Profiler (ADCP) is being used more and more to monitor currents along the Myrtle Beach coast. ADCPs are able to monitor multiple current velocities simultaneously at different depths, and this provides them with a better understanding of the water movement. They are best suited to handle the complex marine topography of the area, including the estuaries and coastal waters.

4. How do ADCPs based on the Doppler principle work?

ADCPs operate on the Doppler principle. They emit acoustic pulses (sound waves) into the water. When these sound waves encounter small particles in the water, such as plankton, sediment, or small air bubbles, the particles scatter the waves. The ADCP measures the frequency shift of the scattered waves.

If the particles are approaching the ADCP current profiler, then the frequency of scattered waves will be higher than the frequency of incident waves. If the particles are receding, then the frequency of scattered waves will be lower. Through the high-precision measurement of these frequency variations, the ADCP is able to calculate the water velocity at multiple depths.

Most ADCPs use greater than one beam to measure the three - dimensional water motion. A four - beam ADCP is an example, which is able to approximate the horizontal and vertical components of current velocity. It enables high - resolution portrayal of complicated water movement, including the presence of vertical shear (e.g., change in current speed with depth) and eddies (circularly oriented current features).

5. What does high-quality measurement of Myrtle Beach coastal currents require?

For high-quality measurement of Myrtle Beach's coastal currents, several things are required. Reliability of materials is crucial. Because of the corrosive conditions of the saltwater and estuaries, the ADCPs and other instrumentation must be made of corrosion-resistant material. Titanium alloy is ideal for ADCP casings. Titanium is also highly resistant to corrosion, which aids in ensuring the equipment lasts longer. This reduces the need for repeated replacement, which is especially important for long-term monitoring programs.

Weight and size are factors as well. Light, small ADCPs are easier to transport and deploy, especially to shallow, sometimes difficult-to-access sites close to Myrtle Beach. Fieldwork has the benefit in this case, as researchers are able to easily move the equipment to different sites of measurement.

Low power consumption is necessary, particularly in long-term monitoring. Since the fact that ADCPs are usually battery-operated, having power-consuming elements be low will allow the equipment to be durable enough without the need to frequently change batteries. This will be of particular importance in the remote coastal area where it may be difficult to access power sources.

Cost-effectiveness is also an important factor, especially for extensive monitoring projects. Well-priced but reliable ADCPs are highly desired. China Sonar PandaADCP is an example of a product that makes a fair trade between price and capability. Built totally of all-titanium alloy, it is robust in the harsh sea environment and yet economic.

6. How to Select appropriate equipment for current measurement?

The equipment selection for current measurement off Myrtle Beach varies according to the application. Ship-mounted ADCPs are appropriate for broad-scale surveys. They can be mounted on research ships and can continuously measure currents as the ship travels along the coast, estuaries, and the Intracoastal Waterway. This gives a broad-scale observation of the current patterns in the region.

Bottom - mounted or moored ADCPs are also ideally suited for fixed - point, long - term monitoring. They can be placed on the seafloor or at the bottom of the Intracoastal Waterway at strategic locations close to Myrtle Beach and record current data for months or even years. This helps in the study of long - term trends in coastal currents.

Buoy - moored ADCPs may be used to observe surface - level currents. They are relatively easy to deploy and recover, and therefore are suitable for short - term study or for making a quick check of surface - current conditions.

Frequency is a major consideration in choosing an ADCP meter. For water depths of less than 70m, a 600kHz ADCP is sufficient. It yields sufficient resolution to estimate currents for the relatively shallow coastal and estuarine waters along Myrtle Beach. At depths to 110m, a 300kHz ADCP is suitable, and for still deeper waters, a 75kHz ADCP would be suitable to 1000m. Lower frequencies are able to penetrate deeper but yield lower resolution than higher frequencies.

There are several well-known ADCP brands, such as Teledyne RDI, Nortek, and Sontek. But for those who are looking for a low-cost option without compromising on quality, the ADCP supplier China Sonar's  PandaADCP is a great option. More information can be obtained on its official website: https://china-sonar.com/.

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