| Kaali crater | |
|---|---|
  Kaali crater Impact location in Estonia | |
| Impact crater/structure | |
| Confidence | Confirmed |
| Diameter | 110 m (360 ft) |
| Age | 3237+/-1014C yr BP |
| Location | |
| Coordinates | 58°22′22″N22°40′10″E / 58.37278°N 22.66944°E /58.37278; 22.66944 |
| Country | Estonia |
Kaali is a group of ninemeteoritecraters in the village ofKaali on theEstonian island ofSaaremaa.[1] Most recent estimates put its formation shortly after 1530–1450 BC (3237 ± 1014C yr BP).[2] It was created by animpact event and is one of the few impact events that has occurred in a populated area (other ones are:Henbury craters in Australia andCarancas crater in Peru).
Before the 1930s, there were several hypotheses about the origin of the crater, including theories involvingvulcanism andkarst processes. Its meteoritic origins were first conclusively demonstrated by Ivan Reinvald[3] in 1928, 1933 and 1937.
The impact is thought to have happened in theHolocene period, around 3,500 years ago.[4] The estimates of the age of the Kaali impact structure (Saaremaa Island, Estonia) provided by different authors vary by as much as 6,000 years, ranging from ~6,400 to ~400 years before current era (BCE). Analysis ofsilicate spherules in Estonian bogs show that the possible age of the impact craters could be approximately 7,600 years.[5] A study based on elevatediridium signal in a nearby bog suggested the much younger age of 4th century BC.[6] The craters were formed by a meteor with an estimated impact velocity of between 10 and 20 km/s (6.2 and 12.4 mi/s) with a total mass of between 20 and 80 metric tonnes. According to some researchers the meteor arrived from the north-east.[7]
At an altitude of five to ten km (20,000 to 30,000 ft), the meteor broke into pieces and fell to the Earth in fragments, the largest of which produced a crater with a diameter of 110 m (360 ft) and a depth of 22 m (72 ft). The explosion removed approximately 81,000 m3 (2,900,000 cu ft) of dolomite and other rocks and formed a 7 to 8 km (20,000 to 30,000 ft) tall, extremely hot gas flow. Vegetation was incinerated up to 6 km (3.7 mi) from the impact site.[7]
Lake Kaali (Estonian:Kaali järv) is on the bottom of this crater. Eight smaller craters are also associated with this bombardment of meteor fragments. Their diameters range from 12 to 40 m (39 to 131 ft) and their respective depths vary from one to four metres (3.3 to 13.1 ft). They are all within one kilometre (0.62 mi) of the main crater.
According to the theory of more recent impact, Estonia at the time of impact was in theNordic Bronze Age and the site was forested with a small human population. The impact energy of about 80TJ (20kilotons of TNT) is comparable with that of theHiroshima bomb blast. It incinerated forests within a six km (3.7 mi) radius.[8]
Scholars, such as Karl Kello,[9] maintain that the event featured prominently in regionalmythology. It was, and still is, considered asacred lake. There is archaeological evidence[clarification needed] that it may well have been a place of ritualsacrifice. At some point during the earlyIron Age, the lake was surrounded by a stone wall 470 m (1,540 ft) long, with a median width of about 2.5 m (8.2 ft) and an average height of 2.0 m (6.6 ft).[citation needed]
Finnish mythology has stories that mayoriginate with the formation of Kaali. One of them is in runes 47, 48 and 49 of theKalevala epic:Louhi, the evil wizard, steals the Sun and fire from people, causing total darkness.Ukko, the god of the sky, orders a new Sun to be made from a spark. The virgin of the air starts to make a new Sun, but the spark drops from the sky and hits the ground. This spark goes to an "Aluen" or "Kalevan"[10] lake and causes its water to rise. Finnish heroes see the ball of fire falling somewhere "behind theNeva River" (the direction of Estonia fromKarelia). The heroes head in that direction to seek fire, and they finally gather flames from aforest fire.
According to a theory proposed byLennart Meri, it is possible that Saaremaa was the legendaryThule island, first mentioned by ancient Greek geographerPytheas, and the nameThule could have been connected to theFinnic wordtule '(of) fire'[11] and the folklore of Estonia, which depicts the birth of the crater lake in Kaali. Kaali was considered the place where "The sun went to rest."[10]
The asteroid4227 Kaali is named after it. Except for their names, there is no connection between this asteroid and the crater.
In 2023, archaeologists analysed theBronze AgeMörigen Arrowhead, found in Switzerland; it was made of meteoritic iron whose composition suggested its origin from the Kaali meteorite.[12]
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58°22′22″N22°40′10″E / 58.37278°N 22.66944°E /58.37278; 22.66944
| Records | ||
|---|---|---|
| Preceded by | The lastimpact event onEarth 1300 BC – present | Succeeded by Incumbent |
