<Tr> <Td> Wapshilla Ridge flows </Td> <Td> ~ 15.5 </Td> <Td> Columbia River Basalt Group, United States </Td> <Td> 5,000--10,000 </Td> <Td> Member comprises 8--10 flows with a total volume of ~ 50,000 km </Td> <Td> </Td> </Tr> <Tr> <Td> McCoy Canyon flow </Td> <Td> 15.6 </Td> <Td> Columbia River Basalt Group, United States </Td> <Td> 4,300 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> Umtanum flows </Td> <Td> ~ 15.6 </Td> <Td> Columbia River Basalt Group, United States </Td> <Td> 2,750 </Td> <Td> Two flows with a total volume of 5,500 km </Td> <Td> </Td> </Tr> <Tr> <Td> Sand Hollow flow </Td> <Td> 15.3 </Td> <Td> Columbia River Basalt Group, United States </Td> <Td> 2,660 </Td> <Td> </Td> <Td> </Td> </Tr>

What is the biggest volcano eruption in the world