growing crater on field

[mollykins]

I moved to my house about 8 years ago and when i first moved there was a slight dip in one of the fields, barely noticeable, but now when i walk or cycle past it, i can't even se the bottom unless i actually go into the field, plus it has grown lengthways aswell.

What is it and why is it 'growing'?

If this helps, i moved from about half a mile away and the soil there was very sandy but it is very clayy here, which shows how much the soil can change in this area.

[paddywak]

Do you live in one of the old mining areas? as subsidence is always a problem especially in the areas where the mining industry has a very long history as many of the early pits did not keep records as to just where they were operating whether it is a ming area or not I think I would be pressing somebody to do some research as there is obviously something wrong to cause this amount of damage, perhaps an underground water course what ever It definatly needs checking

[willow66]

I agree with paddywak that this does need investigating further. In Clay soil areas you can have underground water areas and springs.
Another idea is that a large amount of rubbish or demolished building debris has been buried using large excavator machinery. This would have been buried before you moved in. Over time the air pockets around bulky debris start to fill in and the ground forms a depression. A usual indicator that large amounts of debris have been buried is that lots of excess soil will not fit back into the hole. If there are any mounds or planted embankments in the close area this is usually the original soil from the hole.
Above all get it investigated further.

[mollykins]

Its a farmers field with sugar beet or somekind of grain gorwing on it. There's no kind of mining anywhere near to here and i've never heard of any being done in the past. Plus there are plans for it to have houses ect built on it but they havent yet because of the recession but i've seen people with all kinds of geographical equipment surveying the area.

[mollykins]

But i'm not sure if it 'grows' on its own but it definately gets bigger every time a tractor ect goes over it.

[coalgirl]

Do not know where you live but if there is salt underground it could be a salt sink. Quite common in parts of Cheshire

[mollykins]

East Suffolk, as much as as you get in Great Britain.

[mollykins]

*east (as much east as you get)

[mollykins]

I measured it on google earth (the pictures for ym area have been updated and you can make it out now.) It is roughly 20metres by 70metres.

Could it be thats i'm hilusinating that its getting biggger, and its where a bomb was dropped on it, i know the nearby town was a target for several reasons, and anything within 3 miles of the target was a hit, which is where the crater is.