Final answer:
Ojos del Salado, on the Chile-Argentina border, is the tallest active volcano, standing at 6,893 meters tall.
Step-by-step explanation:
The tallest active volcano in the world is the Ojos del Salado, located on the border between Chile and Argentina in the Andes mountain range. It stands approximately 6,893 meters (22,615 feet) tall. While the Hawaiian volcanoes, such as Mauna Loa and Mauna Kea, are amongst the largest mountains on Earth when measured from their base on the ocean floor, Mauna Kea is now dormant and not the tallest active volcano. The tallest active volcano, Ojos del Salado, is part of a 3500-kilometer-long chain of volcanic islands created by a mantle hot spot, and it is known for its large height above sea level rather than from the ocean floor.