993–994 carbon-14 spike

[4][5][6] In 2021, a scientific paper used the 993–994 carbon-14 spike as a benchmark in dendrochronology (tree-ring studies) to precisely determine that Vikings were present in L'Anse aux Meadows in Newfoundland exactly 1000 years prior, in 1021 AD.

[4][5][6] The historical observations do not completely prove the cause of the 993-994 14C spike but show evidence of a strong solar event taking place late 992, as they were recorded within a relatively short time frame.

[4][6] In the Korean Peninsula, between December 992 and January 993, a text described "heaven's gate" opening one night.

[4] Another set of observations, made December 26, 992, mentioned a light as bright as the sun shining for an hour, then reddening the sky, before vanishing completely.

[4] In the Ulster region of present-day Northern Ireland on December 26, 992, texts described the sky as "blood-red" and having a "fiery hue".

Fig. 1: The carbon-14 spike can be seen 993-994 CE. Colored points represent a studied region around Sweden (NH0) and Japan (NH2); yellow points represent the Japanese cedar analyzed in the study. [ 1 ]