Featured 

 Exhibit 

 for January 



Vol 



canoes: 



Earth's 

 Fiery Activity 



By BERTRAM G. WOODLAND 



Curator, Igneous and Metamorphic Petrology 



V. 



olcanism, for most of us, conjures 

 up visions of large volcanic cones, erup- 

 tions of lava and ash, or the brilliant dis- 

 plays of lava fountains seen against the 

 sky at night. Actually these are only the 

 surface manifestations of the vast tur- 

 moil and unrest existing within the earth. 

 Volcanic outbursts are not only spec- 

 tacular natural events but sometimes re- 

 sult in great damage and loss of life. 

 Many catastrophes have been recorded : 

 among the earliest is that of the destruc- 

 tion of Pompeii and Herculaneum dur- 

 ing the eruption of Vesuvius in August, 

 a.d. 79. Letters written by Pliny the 

 Younger describe this outburst, which 

 caused the death of his uncle, Pliny the 



Night scene during eruption of Volcan Izalco in El 

 Salvador — Central America's most active volcano. 



Elder. The explosive discharge of large 

 volumes of ash and rock overwhelmed 

 the population. Dust and gases asphyx- 

 iated many and the ash buried them in 

 their cellars, so that many centuries later 

 excavations of the site revealed the forms 

 of inhabitants preserved in the volcanic 

 ash. As it had not erupted for many 

 hundreds of years, these people appar- 

 ently did not realize that Vesuvius was 

 a volcano, although the Romans were 



fully aware of volcanic eruptions and 

 considered them to be the activities of 

 Vulcan, their god of fire, from whom the 

 name volcano was derived. 



Another devastating eruption occur- 

 red on the island of Martinique on May 

 8, 1902. A violent explosion on Mount 

 Pelce drove out a great incandescent 

 cloud of gases and pumice which, travel- 

 ing at more than 300 miles per hour, en- 

 (Continued on next page) 



January Page 5 



