VULCANISM, ETC., IN ICELAND. .501 



of which, according to F. Jonstriip, represents 310,000,000 of cubic 

 meters. Tb« craters are divided into three groups, of which the .south- 

 erly is 475 meters, and the northerly 422 meters above t^ea level. The 

 highest crater extended in 1876 to 34 meters above the plain. 



(8) Group of the volcanoes of Myvatn. — The surroundings of the lake 

 My vatn constitute a very remarkable volcanic region ; it is nearly entirely 

 covered with lava beds strewn over with craters, which give it the aj)- 

 pearance of a lunar landscape. To the east of the farm of IleylijaldUlh 

 stretches out a long chain which terminates in the volcano of LeirhHiikr, 

 in the neighborhood of which the grand eruptions of 1724-1730 took 

 place. Into the same perioil fall other eruptions, issuing from the 

 Krajla, to the east of the Leirhnukr, from the ffrossadalr, the Bjurnar- 

 Jiafj, and from another crater in the vicinity of the Reylgahlidharwl, on 

 the east slope of the chain of Daljjall, craters all within a short dis- 

 tance from each other and in a right line south of the Leirhnukr. 

 Several extensive solfatares occur in the vicinity, especially at Isama- 

 fjall. The annals mention besides, still without indicating the locality, 

 several eruptions, the greater part of which undoubtedly have taken 

 place in the unknown regions which surround the Vatnajokull. 



The various lists indicate quite a number of volcanic eruptions in 

 sections, in which, according to the annals, such phenomena have not 

 occurred within historic times. Likewise one might discard the fol- 

 lowing localities as places of eruption : Asmundaruupr, Thoreyjarnupr, 

 HofsjokuU, Balvjokull, Theistareykir, FremriNamar, Hvertjall, Saud- 

 fellsjokull, Mosfell, Herdhubreidh, Skaptarjokull, Breidhamerkrjoknll, 

 Thorsmork, and Torfajokull. It is true, there are craters in some of 

 these localities, but there Is not one historical proof of their eruptions. 

 The foreign publications repeat many errors relative to the situations 

 of the volcanoes of Iceland, caused by the imperfect knowledge which 

 their authors possessed of the topography of this country, 



CHRONOLOGICAL LIST OF VOLCANIC ERUPTIONS AND EARTHQUAKES 



IN ICELAND. 



900 (approximately). Eruption of the Katla. The entire region from 

 the Eyjara and the HolmsJi to the river Kalm, north of the Alptaver, 

 and the district of Dynsk6gahverfi were completely devastated. At 

 about the same time the sandy plain of Solheium appears to have bee)i 

 subjected to the action of water and ice, whereby the course now called 

 Jokulsa 4 S61heimasamli seems to have been formed. Several lists 

 multiply this eruption, dating them in 894 and 934, but tliere is no cer- 

 tainty as to the correctness of these dates. 



950 (approximately). Eruption of the Uldborg and formation of the 

 lava current of Borgarhinun. The farm of Hripr formerly stood on 

 the site of the present crater. 



1000. Eruption on the EelUslwklM and formation of lava stream of 

 Thurr^rhraun. 



