How can I measure the terrestrial tide on my place?

[Baluncore]

Interesting.
I was wondering how much rock there was above the water table, but since you don't give the surface RL of the well I thought I would try Google Earth. You appear to be giving station Lat/Long coordinates for wells in a regional mapping grid rather than in WGS84 = GPS, as used by Google Earth and SOLID. What grid are you using?

My SOLID is now working and seems to agree close enough with yours, give or take the couple of miles possible error in location.

 

[gNat]

No, those are WGS84 coordinates in decimal degrees. I've attached the Google map of Pink Hill station using the coordinates given on the previous image. The wells are the three dots to the east of the location symbol.

Land surface elevations (feet above MSL):
Pink Hill 126
Gibsonville 648
Marble 1,711
Troutman 816
Tater Hill 4,060
Oxford 462
Olivers Crossroad 45

 

[anorlunda]

I'm having trouble visualizing the definition of Earth tide.

1. Are we saying that the entire continental shelf is rising and falling relative to the center of the Earth? What happens with the mantle underneath the continent?
2. Or is it stretching/shrinking near the surface more than being displaced up/down. I would think that stretching/shrinking would cause interstitial water to move from the rock to the cracks and voids, thus changing water level in wells relative to the surface instruments, thus making water level a sensitive indicator.
3. Or is is that the entire globe from Earth's core to the surface is distorted in the ellipsoid direction due to tides?

Wikipedia says #3, citing a magnitude of about 1 meter.
https://en.wikipedia.org/wiki/Earth_tide

But if the whole globe is distorted, the distance between the top and the bottom of a well hole would remain nearly constant. #3 also makes me think of Jupiter's moon Io, which is heated to the extreme by frictional heating by tidal motions. Is Earth's internal heating due to friction significant relative to radioactive decay?

 

[Baluncore]

3, Or is is that the entire globe from Earth's core to the surface is distorted in the ellipsoid direction due to tides?

That is the case.
The Earth appears to be elastic with an average rigidity somewhere between glass and steel. The globe has an immediate elliptical tidal distortion with a maximum trough to peak radial range of 51.5 cm, when everything acts in the same direction.

But if the whole globe is distorted, the distance between the top and the bottom of a well hole would remain nearly constant.

Yes. It remains almost constant. But:
The mass of rock near the surface is fixed. The tide results in a minute change of local little g, so the weight of the rock and it's downward force changes with the tide. The elasticity or compressibility of porous rock is greater than solid rock, so the volume of more porous rock changes more under compression. The water is squeezed out of the deep rocks and must move a few millimetres up in the formation. The percentage pore volume at the water table sets the vertical range sensitivity of the inverted tide in the well.

In effect, the rock of the aquifer is a compression spring supporting the weight of all the rock above. The space around that spring is filled by non-structural fluid, which is ground water. (The wet rock has weight reduced by buoyancy in that hydrostatic fluid). As the rock spring changes length, water is displaced in the vertical direction. The reduction in rock column length is small, but it is added, to differentially raise the water level in the well.

 

[rtx22]

Yes, it is used to eliminate the Earth tide from geological gravity surveys.
There is one here; https://geodesyworld.github.io/SOFTS/solid.htm#link2

Has anyone compared the software data with the data from the gravimeter or the pendulum in reality and not with data from the internet? The superconducting gravimeter gives me other data, data that do not coincide with those of the program, not always.
There are also other tidal components like M2 S2 Ssa Sa MmN2 K2 KI OI PI that induce major variations in reality that the software does not have implemented.
Test yourself if you have a gravimeter.

 

[Baluncore]

Has anyone compared the software data with the data from the gravimeter or the pendulum in reality and not with data from the internet?

Can you please give a link to the tidal data on the internet.

The Earth tide computed by the “Solid” software correlates remarkably well with the borehole data observed. "Solid" is used to reliably remove tidal changes from gravity surveys.

For ocean tides, the coastal profile geometry selects and amplifies many different components. Those resonances are insignificant in the solid Earth tide, so those components can be ignored.
Land-based measurement of little g near the coast, requires allowance for the tidal movement of the mass of nearby ocean water.

The superconducting gravimeter gives me other data, data that do not coincide with those of the program, not always.

Which superconducting gravimeter are you referring to, and where is it located ?