HS Turku “As if a bomb had fallen” – Ulla Järvi’s yard pounded like a boulder the size of a car, the geologist comes up with only one sensible explanation

Rock water that has entered the cracks and has alternately frozen and thawed over a long period of time.

“I can’t think of another sensible reason,” says the specialist Timo Ruskeeniemi Geological Survey of Finland.

Now we are talking about boulders that fell into the yard of two houses in Salo on Monday morning.

Ruskeeniemi has read the relevant news, but he has not visited that rock and does not know more about it. He says the rock looks shaped by nature based on the pictures.

“When there are different, horizontal and vertical cracks in the rock, it may start to separate from the rock like blocks. When water enters the crevices and when the water freezes and melts alternately long enough, the stone sets in motion, ”he says.

Another reason that can cause movement is the roots of the trees.

Boulders According to Ruskeeniemi, detachment from the rocks is not terribly common, but it does happen.

“Quite rarely, of course, does this happen that anyone gets yarrows in their yard. If there is such a place as here in Salo, yes it is always possible. Especially when the rock is about to break what it seems to be, ”he says.

Ruskeeniemi says that Salo does not have a greater risk of rock splitting than anywhere else in Finland.

“Finland’s bedrock is about two billion years old. We have a great variety of rocks, and what kind of cracking comes into the rock depends on the type of rock. Here, too, the Salo region has typical Finnish rock types. ”

Granite rocks are more easily blocked than, for example, slate.

“If the geometry is favorable, all kinds of stones can move.”

Salon Two stalks dropped down in Haliko. One of them fell Ulla Järven to the yard. He says it is precisely the granite rock.

According to the lake, probably one piece came off the rock, which split in two when it fell. One boulder demolished a neighbor’s sauna building, another crashed into the side of Järvi and her husband’s car. Fortunately, no injuries occurred.

The boulders collapsed to the ground early in the morning, between five and a half to six.

“We woke up to it with my husband, our neighbor was already awake,” Järvi says.

He said the thump was huge, as if the bomb had fallen.

Rock at the foot are a dozen houses, the oldest of which is about a hundred years old. The lake has lived in the place for over 30 years. There are no big boulders in the courtyards of the houses, so the same has hardly happened before in that place.

“Some stone is weathered from there, just a small piece of it,” he says.

The lake says we move around the rock because it is a scenic spot.

It is not yet known when Järvi and his neighbors will get home. Residents of a total of four houses are now in emergency accommodation, as the nearest neighbors were also evacuated for safety.

On Wednesday, Järvi was able to visit home to pick up goods.

“We are only allowed to visit there with a representative of the city’s building inspectorate, it is now an area classified as life-threatening,” he says.

Ruskeeniemi says it would be good for an expert to visit similar places.

He says professionals are able to identify blocks that are loose and can move. If necessary, the stone in poor condition can be stabilized, for example, by bolting or netting.

According to Ruskeeniemi, for example, when driving tunnels, the rock is examined. Perhaps no one is keeping an eye on the natural rocks.

“These natural fronts are such that they don’t usually pay attention to it.”