The enigmatic Menominee crack is indeed a strange geological phenomenon. It stands even today as a mystery of history.

Seismology experts have been closely observing a crack that appeared in Menominee, Michigan about half a dozen years ago. They may be close to discovering the real reason behind this crevice.

The study was published this week in the journal Seismological Research Letters. Existing in the rustic locale of the Michigan woods, this mysterious fissure has puzzled geologists since its first appearance in 2010. A group of scientists have conjectured that it is a pop-up feature. It is at a spot that lies along a ridge.

The phenomenon known as a pop-up is basically when rocks buried near the earth wedge outwards after being pressurized by ice or stones. They are often termed A-tents due to their peculiar shape.

Usually after a glacier has receded, the earth crops up in the form of a widow’s peak. Or the rocks are displaced and the particular formation gets exposed in the shape of a quarry.

The only problem is that the last glaciers retreated from the Menominee region some 11,000 years ago. Neither is there any quarry in the area.

No other pop-up has been seen so far so this one remains an isolated phenomenon. And it is a singular and a unique event indeed. The local folks heard a loud noise during the night and when they woke up the crack was visible in the woods.

This crack ran for 110 meters and went down into the ground to a depth of 1.7 meters. Tree trunks were like broken toothpicks on either side of the fracture in the earth. The researchers spoke of how it was a big surprise. In fact, it was like nothing ever seen before.

The dramatic geological feature may have been caused by an earthquake. But the seismologists don’t report any such series of tremors that may have been responsible for the phenomenon.

It is still a very mind-boggling event and one that is cataclysmic to boot. A pop-up is actually a sort of seismic refraction. The seismic waves travel through the earth’s mantle and reach the crust resulting in the fissure.

As a pop-up, this enigma required some investigation and close observation. The digging up of a huge pine tree a day before the appearance of the pop-up may have been the last straw that led to the proverbial breaking of the camel’s back. There is very little chance of a repetition of this event so the locals do not need to worry too much regarding the pop-up.