The Hawaiian Islands are at the southeast end of a chain of volcanoes that began to form more than 70 million years ago. Each island is made of one or more volcanoes, which first erupted on the floor of the Pacific Ocean and emerged above sea level only after countless eruptions. Presently, there are six active volcanoes in Hawaii.
The USGS Hawaiian Volcano Observatory (HVO) is also responsible for monitoring active volcanoes in American Samoa, which include:
READ FULL ARTICLE: Active Volcanoes of Hawaii | U.S. Geological Survey (usgs.gov)