Where is this?

[bobpbx]

I Iike John's answer.

 

[Boyd]

In the new LIDAR viewer... coming soon.

 

[pinelandpaddler]

In the new LIDAR viewer... coming soon.

View attachment 19939

Whoa!

 

[pinelandpaddler]

Spoil piles from dredging?

Negative.

 

[pinelandpaddler]

Thanks for checking it out. I was surprised to discover that the road was only built in the 1930s. At first I hypothesized that the woodwork might have supported an earlier bridge but topographic maps and aerial imagery appear to disprove this idea.

If my travels take me to River Road Clam House this weekend, I will take a little detour and give it a look too.

I can see that it was built sometime between 1931 and 1942. Do you have more specific information?

 

[smoke_jumper]

Negative.

Ok. Now I have 2 questions.
1. Are they naturally occurring?
2. Were they created less then 50 years ago? I can’t really see them on older aerials.

 

[bobpbx]

What about spoils from mosquitoe control ditches?

 

[smoke_jumper]

What about spoils from mosquitoe control ditches?

Are we talking about the circles or the straight ditches?

 

[pinelandpaddler]

Ok. Now I have 2 questions.
1. Are they naturally occurring?
2. Were they created less then 50 years ago? I can’t really see them on older aerials.

1. Yes
2. Most if not all are less than 50 years old.

 

[pinelandpaddler]

What about spoils from mosquitoe control ditches?

Nope.

 

[Menantico]

Some sort of natural subsidence?

 

[smoke_jumper]

1. Yes
2. Most if not all are less than 50 years old.

Clusters of Phragmites?

 

[manumuskin]

Where is this now? Another very aggravating closure. I use this road at least a couple times yearly, and NOBODY was abusing it. Makes me sick to my stomach to see this happening.

View attachment 19928

by the tracks I"d say someone is ignoring the signs as so would I.

 

[pinelandpaddler]

Clusters of Phragmites?

You got it!
Isolated clusters expand radially into circles. As they expand, the soil is raised by bioturbation. I’d like to better understand that process.

Apparently, phragmites have been in the area for millennia. Why have they taken over the meadows only recently?

 

[pinelandpaddler]

Thanks for checking it out. I was surprised to discover that the road was only built in the 1930s. At first I hypothesized that the woodwork might have supported an earlier bridge but topographic maps and aerial imagery appear to disprove this idea.

If my travels take me to River Road Clam House this weekend, I will take a little detour and give it a look too.

I took a quick look today but didn’t see the structure.

 

[bobpbx]

You got it!
Isolated clusters expand radially into circles. As they expand, the soil is raised by bioturbation. I’d like to better understand that process.

Apparently, phragmites have been in the area for millennia. Why have they taken over the meadows only recently?

When John said that yesterday I dismissed it, but then I took the bridge over the mullica at green bank on google street view and the round spot on the lidar did indeed turn out to be phragmites. They are highly rhizomotous, so maybe as they expand the root system actually pushes the earth up. Just a theory.

 

[Boyd]

The answer was right under my nose, but I didn't realize until now!

https://boydsmaps.com/pines/#17/39.600509/-74.575812/midatlidar/0/0/

 

[pinelandpaddler]

When John said that yesterday I dismissed it, but then I took the bridge over the mullica at green bank on google street view and the round spot on the lidar did indeed turn out to be phragmites. They are highly rhizomotous, so maybe as they expand the root system actually pushes the earth up. Just a theory.

That’s what I’m thinking. How do the roots raise the ground, and why only at the outer edge of the circle?

 

[smoke_jumper]

You got it!
Isolated clusters expand radially into circles. As they expand, the soil is raised by bioturbation. I’d like to better understand that process.

Apparently, phragmites have been in the area for millennia. Why have they taken over the meadows only recently?

When I was thinking it could be phragmites I never realized they grew in circular clusters. Is the ground actually pushed up or is the base of the plants so dense that the LiDAR sees it as ground. I’d imagine the root system would be more dense around the edges simply because there’s more nutrients there. They could be so thick that they are choking themselves out in the center.

 

[pinelandpaddler]

When I was thinking it could be phragmites I never realized they grew in circular clusters. Is the ground actually pushed up or is the base of the plants so dense that the LiDAR sees it as ground. I’d imagine the root system would be more dense around the edges simply because there’s more nutrients there. They could be so thick that they are choking themselves out in the center.

I think some ground-truthing is in order!