Atgeir Atgeir An atgeir, sometimes called a "mail-piercer" or "hewing-spear," was a type of polearm in use in Viking Age Scandinavia and Norse colonies in the British Isles and Iceland. It is usually translated in English as "halberd", but most likely closer resembled a bill or glaive during the Viking age. Another view is that the term had no association with a specific weapon until it is used as an anachronism in saga literature to lend weight to accounts of special weapons. Later the word was used for typical European halberds, and even later multipurpose staves with spearheads were called "atgeirsstafir".
Types of volcanic eruptions propels it forward. Phreatomagmatic eruptions are another type of volcanic eruption, driven by the compression of gas within magma, the direct opposite of the process powering magmatic activity. The third eruptive type is the phreatic eruption, which is driven by the superheating of steam via contact with magma; these eruptive types often exhibit no magmatic release, instead causing the granulation of existing rock. Within these wide-defining eruptive types are several subtypes. The weakest are Hawaiian and submarine, then Strombolian, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions; the strongest eruptions are called