About: http://webisa.webdatacommons.org/424045732

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Researchers have considered all kinds of processes to explain the events, including volcanic activity and comet impacts.
http://www.w3.org/ns/prov#wasQuotedFrom	newscientist.com