Viking halberd difficult to know what kind of weapon is being described in these translations, or the original texts. Many of these terms are shown below. The "atgeir" was a type of bill or halberd, from Old Norse "geirr", "spear". The "atgeirr" is thought to have been a foreign weapon and is rarely mentioned in the sagas, but is famous as the favorite weapon of Gunnar of Hlíðarendi. In Njál's saga this weapon is shown as used mostly for thrusting, but also for hewing. The "höggspjót", literally "hewing spear", takes its name from Old Norse "högg", "stroke, blow, slaughter, beheading" and "spjót",
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