Extreme Surf Affects Jaltemba Bay Beaches

Extreme Surf Affects Jaltemba Bay Beaches

       Tara A. Spears

For the third consecutive year, a higher ocean level and violent surf has caused problems along the Pacific Coast communities. The impact of these wild waves range from eroding beaches to property damage as well as an increase in accidental drownings as visitors go in the ocean when there is dangerous undertow. The roiling surf is mesmerizing to watch but you must be aware of the ocean’s power and respect it.

In the years that I have lived in Jaltemba Bay, I’ve seen the shoreline move inland. The north beach of La Penita has sustained the most obvious damage. As the overall higher water level at all tides has pounded the seawalls of oceanfront homes while at the same time the bottom sand that the wall rests on has eroded from the fierce undertow. The high tides repeatedly splash over the top of the seawall, and since water always seeks the lowest return, the water pulled out on the tide has also taken the sand base. This is the natural power of water.

Ocean scientists have theorized for years that the melting ice cap would have drastic effect on the world’s oceans. Today’s highest tides become the new normal do to climate change. If you wonder what sea level will look like with ongoing climate change, go to a beach during the highest tide of the year: in Jaltemba Bay it is generally December and February. Often the highest tides are the result of the influence of the sun on the earth and the moon also has an effect that plays a crucial role as well. The graphic shows the dynamics of tides.

 

The highest spring tide of the year happens when the orbit and alignment of the sun and moon reinforce at their closest and furthest extremes from earth – this is what is often colloquially called a “king tide,” although it’s not a scientific term.

The word “tide” is the term used to define the alternating rise and fall in sea level with respect to the land, produced by the gravitational attraction of the moon and the sun. Each day, there are two high tides and two low tides. The ocean is constantly moving from high tide to low tide, and then back to high tide. There is about 12 hours and 25 minutes between the two high tides.

Tides are a complex interaction of the gravitation attraction and rotation of the earth, sun, and moon The complex interaction of gravitational attraction that create tides are also affected by oceanic phenomenon such as waves and currents. Local weather conditions contribute to the force of the tides.                          

Twice a month when the pull of the moon and sun on the Earth are in alignment, the ocean tides are highest – these are known as “spring tides,” in the sense of bursting forth or jumping up, and occur during the full and new moon. Spring tides are bigger than “neap” tides, which occur during the other two major phases of the month, when the moon is either in its first or third quarter.                                    

The most common cause of natural beach erosion is from the action of the wind and waves. Over long periods of time these can erode the coastline, but this process may occur faster if a significant weather event, such as a hurricane, impacts the area. It is also believed that rising sea levels may cause erosion by creating alternative tidal patterns. Coastlines with soft sediments and open stretches of beach are the most easily affected by the movement of waves and tides. To complicate the Jaltemba Bay beach problems, there are several man-made jetties installed plus natural rock outcroppings at the north end. These features greatly impact the residential beach area. As you can see in the the north beach photo of the old cemetery, another row of graves has been claimed by the sea due to rising water level and the rough surf.      

  

If you just have to dip into the Pacific, be mindful of the strong undertows that exist December through March in Jaltemba Bay- there is a reason the harbor master shuts down boat operation! You can still get wet and boogie board, just don’t go too deep in order to resist the undertow. As waves break on the shore, the water from the previous waves rush out beneath them.

While the rising ocean level can make it challenging to walk the beach these days, it is an amazing sight to see the wild surf in our usually calm bay. It is certainly a beautiful event!