Beachscape
Ocean Park, Washington.
I am not a beach geologist. But I've been observing this stretch of beach long enough to know that the sand feature on the left is unusual. What is going on?
For the past four or five years, there has been a sharp increase in dune building in this area and other spots along the foredunes. I took this photo where the beach path opens onto the top of a ridge formed by a series of dunes.
When we moved here in 2020, there was barely a downward slope in the path behind me that leads back inland to the valley at the base of the next sand ridge. Today, the path is now quite steep and longer because of the accumulation of sand. In fact, a new dune is forming near the beach end of the path, which means the trail climbs steeply for a stretch, levels out, and then climbs again over the baby dune.
In simplest terms (which is all that my limited knowledge allows), I posit that the accelerated dune formation is due to an increase in the force of the prevailing winds and the frequency of wind speeds capable of piling sand into dunes.
The flame shaped feature on the left was carved into the dune by the sand-laden winds during a time when the winds were especially strong. In other words, it is the chute over which the dune-building winds pass on their way inland. Something about the topography at that spot was conducive to the formation of a funnel that directed blowing sand up the dune and beyond.
That's my story, and I'm sticking with it unless someone has a better idea.
That someone turned out to be Chat GPT. It looked at the image and provided the following analysis:
At the crest of the last foredune before the open beach, a flame-shaped depression cuts through the sand, aligned with the prevailing northwesterly winds common to Washington’s Pacific coast. This feature likely formed through aeolian deflation: as wind encountered a subtle topographic dip in the dune ridge, it was funneled into the low point, increasing in velocity and scouring sand more aggressively than in adjacent areas. Over time, this concentrated airflow carved a smooth, tapered channel — a corridor of intensified sediment removal shaped by persistent wind action.
On the north side of this chute-like form, a small dune is beginning to build at a near-right angle to the shoreline. This incipient ridge, anchored by a patch of beachgrass, likely formed in response to localized turbulence or eddying at the edge of the deflation zone, where the wind loses speed and drops its sediment load. The perpendicular alignment of this new dune contrasts with the more linear pattern of foredune growth and suggests a microenvironment of deposition within a broader erosional setting.
Together, the streamlined channel and the offset dune reveal the dynamic interplay of wind, sand, and vegetation. Subtle variations in relief and ground cover amplify wind’s sculpting power, producing a mosaic of erosional and depositional forms even within a few meters of shoreline.
Beachscape
Ocean Park, Washington.
I am not a beach geologist. But I've been observing this stretch of beach long enough to know that the sand feature on the left is unusual. What is going on?
For the past four or five years, there has been a sharp increase in dune building in this area and other spots along the foredunes. I took this photo where the beach path opens onto the top of a ridge formed by a series of dunes.
When we moved here in 2020, there was barely a downward slope in the path behind me that leads back inland to the valley at the base of the next sand ridge. Today, the path is now quite steep and longer because of the accumulation of sand. In fact, a new dune is forming near the beach end of the path, which means the trail climbs steeply for a stretch, levels out, and then climbs again over the baby dune.
In simplest terms (which is all that my limited knowledge allows), I posit that the accelerated dune formation is due to an increase in the force of the prevailing winds and the frequency of wind speeds capable of piling sand into dunes.
The flame shaped feature on the left was carved into the dune by the sand-laden winds during a time when the winds were especially strong. In other words, it is the chute over which the dune-building winds pass on their way inland. Something about the topography at that spot was conducive to the formation of a funnel that directed blowing sand up the dune and beyond.
That's my story, and I'm sticking with it unless someone has a better idea.
That someone turned out to be Chat GPT. It looked at the image and provided the following analysis:
At the crest of the last foredune before the open beach, a flame-shaped depression cuts through the sand, aligned with the prevailing northwesterly winds common to Washington’s Pacific coast. This feature likely formed through aeolian deflation: as wind encountered a subtle topographic dip in the dune ridge, it was funneled into the low point, increasing in velocity and scouring sand more aggressively than in adjacent areas. Over time, this concentrated airflow carved a smooth, tapered channel — a corridor of intensified sediment removal shaped by persistent wind action.
On the north side of this chute-like form, a small dune is beginning to build at a near-right angle to the shoreline. This incipient ridge, anchored by a patch of beachgrass, likely formed in response to localized turbulence or eddying at the edge of the deflation zone, where the wind loses speed and drops its sediment load. The perpendicular alignment of this new dune contrasts with the more linear pattern of foredune growth and suggests a microenvironment of deposition within a broader erosional setting.
Together, the streamlined channel and the offset dune reveal the dynamic interplay of wind, sand, and vegetation. Subtle variations in relief and ground cover amplify wind’s sculpting power, producing a mosaic of erosional and depositional forms even within a few meters of shoreline.