- For the moon of Saturn named after Greip, see Greip (moon).
- For the Gjalp fissure eruption see Bardarbunga.
In Norse mythology, Gjálp and Greip are two giantesses.
Thor's visit to Geirröðr
Thor's Journey to Geirrodsgard by Lorenz Frølich
According to Skáldskaparmál they were daughters of the giant Geirröðr. As Thor was wading across Vimur the river "waxed so greatly that it broke high upon his shoulders". He finds out why.
- "Then Thor saw Gjálp, daughter of Geirröðr, standing in certain ravines, one leg in each , spanning the river, and she was causing the spate. Then Thor snatched up a great stone out of the river and cast it at her, saying these words: 'At its source should a river be stemmed.' Nor did he miss that at which he threw." – Brodeur's translation
Once Thor reaches Geirröðr's dwelling he is offered a seat.
- "Then he became aware that the chair moved under him up toward the roof: he thrust Grídr's rod up against the rafters and pushed back hard against the chair. Then there was a great crash, and screaming followed. Under the chair had been Geirrödr's daughters, Gjálp and Greip; and he had broken both their backs." – Brodeur's translation
The same myth is related in Þórsdrápa, though the giantesses are not named there.
- "The peace-reluctant slayer of the reindeer of the Lister of the peak [Þórr] was put in a fix there, on the dire, grim hat of the giantess [chair].
- They forced the high heaven of the flame of the brow-moon [Þórr's head] against the rafters of the (rock-)hall [cave], and were crushed against the rocks of the plain (of the rock-hall) [floor]. The hull-controller of the hovering chariot of the thunder-storm [Þórr] broke the ancient keel of the laughter-ship [backbone] of both cave-maidens [giantesses]." – Eysteinn Björnsson's translation
Gesta Danorum relates a similar story.
- "[T]hree women, whose bodies were covered with tumours, and who seemed to have lost the strength of their back-bones, filled adjoining seats. Thorkill's companions were very curious; and he, who well knew the reason of the matter, told them that long ago the god Thor had been provoked by the insolence of the giants to drive red-hot irons through the vitals of Geirrod, who strove with him, and that the iron had slid further, torn up the mountain, and battered through its side; while the women had been stricken by the might of his thunderbolts, and had been punished (so he declared) for their attempt on the same deity, by having their bodies broken." – Elton's translation
In Hyndluljóð Gjálp and Greip are mentioned as two of the mothers of Heimdall.
In Haustlöng, Þjazi is called "the son of the suitor of Greip". Greip may be used there as a generic giantess name and the kenning may mean simply "giant".
In a lausavísa composed by Vetrliði Sumarliðason and quoted in Skáldskaparmál, Gjálp is mentioned as being killed by Thor.
- Leggi brauzt þú Leiknar,
- *lamðir Þrívalda,
- steypðir *Starkeði,
- stóttu of Gjálp dauða. – Faulkes' edition
- Thou didst break the leg of Leikn,
- Didst cause to stoop Starkadr,
- Didst bruise Thrívaldi,
- Didst stand on lifeless Gjálp. – Brodeur's translation