Natural Factors Cause Dramatic Change In OC Beach

Natural Factors Cause Dramatic Change In OC Beach
Misc IMG 1665 Edit Edit 08 04 2015

OCEAN CITY — A variety of factors have conspired this week to create a dramatic change in the beach in Ocean City, including a sharp drop-off of as high as four or five feet with a pronounced ledge at the water’s edge.

A combination of high tides, prevailing north-south currents and heavy wave action spurred by a recent full moon, the second in July and a phenomenon known as a blue moon, created a steep drop off with a pronounced edge along the waterfront in the resort. It’s a natural phenomenon that occurs often throughout the year, but because it was created during one of the peak seasons in the summer this week, it has created somewhat of a stir.

Ocean City officials and the Ocean City Beach Patrol are monitoring the change in the beach, although there is little or nothing to do other than let nature run its course. City Engineer Terry McGean said on Wednesday he had been checking out the conditions.

“Coincidentally, I just rode the beach this morning,” he said. “The edge condition occurs along pretty much the entire beach and into Delaware. It is a natural occurrence that we typically see more in the winter and spring.”

McGean offered a somewhat scientific reason for the sudden change to the beach contour.

“It is caused by steep waves with short periods, or the times between waves,” he said. “Looking at some wave buoy data, we had about six hours of these types of waves on Monday night, peaking right around high tide. You will notice that the beach floor in the surf zone has a flatter slope, which is where the material from the upper beach was deposited. The drop-off will naturally flatten out to a shallower slope probably within a week or two.”

Ocean City Beach Patrol Captain Butch Arbin offered a similar explanation.

“A variety of natural factors caused it this time around,” he said. “First, we had two full moons in July, the second being a blue moon, which affect the tides. Second, we’ve seen really steep wave action in the last week or so. Third, there has been a strong current running south to north, which has caused the sculpting of the beach. The contour of the beach in Ocean City isn’t a straight line, which is why you see this sort of carving of the beach at the water’s edge.”

While for the most part, the steep ledge has not created problems for beachgoers going in and out of the water, it has created some challenges for lifeguards.

“The biggest challenge is, the guard stands are sitting right on the ledge because we have to be out in front of everybody on the beach,” said Arbin. “When they have to jump down, they’re dealing with that extra four or five feet. Also, there can be some challenges getting people who are injured off the beach. We had an example of a person who suffered a knee injury and there were some challenges getting her up and over that ledge.”

Arbin said the change in the beach has not created any more dangerous situations for beachgoers, however.

“This has not caused any increase in neck or back injuries,” he said. “Those kinds of injuries are associated with shore breaks at high tide in shallow water and that hasn’t been the case this week.”

The changing ocean contour this week has unveiled some throwbacks to a different era in Ocean City in some places, however.

“Another interesting challenge has been the erosion by the water’s edge scouring away sand that has uncovered the old stone and wooden groins and jetties,” he said. “Some of our guards who have been working with us for years have never seen them.”

For decades, wooden groins or jetties extended out perpendicular to the beach to capture migrating sand and maintain beach widths. Since the advent of beach replenishment in Ocean City, the beaches have been widened to the point the old wooden and later stone jetties have become completely buried. However, the unique phenomenon that created the big shelf this week has exposed some of those old rocks in some places, according to Arbin.

“As far as I know, with a few exceptions, most of them have remained out there on the beach,” he said. “Beach replenishment covered them up, but from time to time we see erosion uncover some of them a little. We’ve seen some of that this week.”

There has been some criticism in recent years that man-made beach replenishment has disrupted the natural migratory patterns on the beach and created different contours on the ocean floor. Some camps also believe beach replenishment has changed wave patterns and increased the frequency and severity of ocean-related injuries. Arbin said the creation of the shelf, or ledge, along the water’s edge was unrelated.

“This has nothing to do with beach replenishment,” he said. “The beach changes all the time by a variety of factors like tides, currents, winds and even moon phases. We are not seeing any more serious injuries. There are a lot of opinions out there, and I try to steer away from opinions and pay attention to what science and nature shows us.”

Another challenge this week to some degree is the creation of the ledge has created an invitation of sorts for beachgoers to dig tunnels and make large holes. For years, the beach patrol has pushed the message about the dangers of digging holes in the sand that can collapse and have serious, or even deadly, consequences. However, Arbin said this week the big ledge has not created any spike in digging incidents.

“The ledge is pretty pronounced in the morning with a sharp edge and a straight drop, but as the day goes on, it wears down pretty quickly from all of that foot traffic,” he said.