Interesting Anomoly

[Jogeephus]

I was recently running a boundary line with a magnetic compass and everything looked like it was going to be a piece of cake since I new where all 4 corners were and one side even had tape marking the line. I followed the tape only to find the line had a big jog in it and the person tying the tape quit and never finished the job. I ran this line twice and could not properly close the line. I put this off and moved to the west line to run it. Nothing was marked on this so I just chopped my way through for about a mile and came up to an old corner and a witness tree which was some 100 feet from where the real corner was. Ran it again in opposite direction and it still did not work out. Three more tries but still it wouldn't work out. I then took a very accurate GPS unit and marked the corners and created a navigation line between the two points. The bearing on this line was almost due North but this did not work out with the compass. To check this, I did some tweaking and established a longer line with a greater sighting distance so I could view the compass in relation to the GPS line only to find the compass was being pulled 17 degrees off for some reason. This "pull" was evident on both sides of the property and explained why things went haywire on the other boundary as well. The 17 degree pull also explained why the other corner was where it was at and was evidence to me that I am not the only one who had trouble in this area since the other corner was set nearly 100 years ago.

The size of the area of this influece is several acres and would resemble a long swath with a width of about 200 yards and an undetermined length but over 1/4 mile which would rule out a buried car or old railroad bed.

Since I have never seen such and wanted some type explanation I called a friend of mine who is a geologist for the defense department. He is one of the head gurus with them and sets determines what geology is best for underground bunkers and storage facilities. Though he gave me several possibilites, many he said "should not" be in my area. Said it was very interesting and gave me a few numbers to call if I want to get someone out there to try to determine what this might be.

Though I've heard of this before, I have never actually seen it. One of the possibilites is it is a meteor under the dirt. This could be it since there is a meteor crater not 3 miles from here that consists of 1500 acres or better. Just think its neat. Anyone got any thoughts?

 

[Nowland Farms]

Joo, wouldn't a large ironore deposit underground affect the magnetic pull of the compass?

 

[Lammie]

Tommyknockers.

 

[dieselbeef]

that property is definitely got ''bad karma''. cease and desist immediately and please transfer all property rights to me immediately so i can assesss the information.

thank you

 

[sidney411]

I don't know anything about using a compass and such, sio this may be a dumb question. What affects the way a compass works? Maybe it has something to do with the earth axis tilting like in that post a while back by Beefy? I'm curious now, let us know if you figure it out.

 

[john250]

No clue.
Now, if you were in Texas I'd say space aliens.

 

[dieselbeef]

maybe you werent holding yer tongue right

 

[milesvb]

I didn't realize anyone actually still surveyed with a compass. Here it is all GPS or total station.

 

[Lammie]

No clue.
Now, if you were in Texas I'd say space aliens.

That what Tommyknockers are. Did you never read any Stephen Kind? I figgered that there wasn't much more to do on an Indiana winter night. It's about this woman that digs up an alien craft and it takes over the area. It is a huge book but really good.

 

[hillrancher]

It was surveyed on true north. Your compass reads magnet north. You will have to find out what the difference is in your area and compensate. I believes it is 3.5 degrees difference in your area without checking the charts not sure.

 

[Jogeephus]

Joo, wouldn't a large ironore deposit underground affect the magnetic pull of the compass?

Iron deposits would definitely throw a compass. My engineering friend suggested this as one of the reasons. What type iron deposit and the cause was the question - if that is the reason. He said that limestone could erode away into the water table leaving nonsoluble deposits of iron. However, in our area this is unlikely since iron deposits are not normally found here. Meteor was another possibility. Lime sink/cavern with underground river another possibility. Another extremely rare but possible possibility is some type magma protrusion from the earths core through a fracture. Though highly unlikely and very rare, these deposits fit the profile and yield diamonds - but I'm sure that is not it either. I'm leaning toward an underground river or a meteorite but I'm going to see if any college geologists would like to look at it.

I didn't realize anyone actually still surveyed with a compass. Here it is all GPS or total station.

The land had already been surveyed and corners concrete corners set. Problem we have with these young buck surveyors is they don't blaze the property lines since with total station and other equipment they don't actually have to walk the property line to set corners. Also, with heavy canopy, multipath error can lead to some pretty discouraging data with GPS.

I don't know anything about using a compass and such, sio this may be a dumb question. What affects the way a compass works? Maybe it has something to do with the earth axis tilting like in that post a while back by Beefy? I'm curious now, let us know if you figure it out.

Magnetism of the earth is what pulls the needle. However, Hillrancher pointed out, the magnetic north and true north are not the same. The deviation from the true north is called the declination. HR is right, our declination is around 3.5 degrees but it changes slightly each year. All my compasses are set to 3.5 or 3.75 depending where I'm working. So the pull from true north in this instance is actually 20 degrees - that's like I'm in Alaska or something.

Also, keep in mind whatever it is that is influencing the magnetism is isolated to a relatively small area. Its got to be iron in origin. But what puts iron in the ground where iron is not commonly found? I guess this is the question. Did it come from above or from beneath? I think its interesting and I hope I can get a definitive answer from a professional geologist. I think its interesting and I would think they would too. My geologist friend wants to see it but he is busy in Nevada right now.

 

[Stepper]

You know Joe, a few years ago i was out in a hay feild and found a round depression in the feild about 2' in diameter and 8" deep with no grass gowing on it. As a matter of fact i found a couple of them just about 100 yards or so apart. And i was tring to figure out what could have caused it.

But i never did figure it out. I wound up taking the loader on my tractor and feeling the depressions in to avoid hitting them while cutting hay.

But not long after i done that i was looking at that feild on the internet using the terra server aerial photos and noticed several round spots in the feild and in other feilds near it. From the air the round spots looked like bear spots in the feilds and all different sizes.

I may be wrong but i think all of thoes spots are made from metor's hitting the earth. The next time you look at any areial photo's look and see if you can see them. You may have already seen them before. But it seems like when you start finding them in one area you will find alot of them in anyone place.

 

[Jogeephus]

Stepper, you are thinking like I am. If you have google earth, you can type in Ten Mile Bay Georgia and this will bring you to a Carolina Bay which is 2.1 miles in diameter. Some speculate that these type bays were formed over 27000 years ago by a meteor shower - others disagree. Anyhow, I don't know where these things came from since I wasn't born yet but they sure resemble moon craters to me. And the anomoly I found is just 1.2 miles west of this next to another smaller pock mark. So IF this bay was formed by a meteor shower, it would be reasonable that a piece of it could have become lodged in the ground a mile from it. But then again, I have walked thru Ten Mile Bay with my compass and never had any trouble there other than making it back to the truck alive - its a devilish place.

 

[bucco]

Go to Google Earth.com and place your cursor on corner points and read Long. and lat. Do the calculations and and you have your square footage.

 

[Jogeephus]

Go to Google Earth.com and place your cursor on corner points and read Long. and lat. Do the calculations and and you have your square footage.

I have the piece of land in the GIS system and can easily calculate everything with a punch of a button. Problem lies in transferring what's on paper onto the ground. This is where it gets tricky since you can't run a compass in this area. I worked around it and have the lines marked on the ground but its just odd to me.

Since I posted this, I've been in contact with a state geologist and emailed him the map data. He is going to compare it to his database and see if they have anything on record. He seems to think its a lime sink which left an iron deposit when limestone eroded away. Still rare since we don't have many iron deposits.