Two of Hawaii's most active volcanoes share the same source, according to scientists' findings (photos included).

The history of Earth spans over 4.5 billion years, and throughout this time, our planet has been in constant motion. Many processes occur within the planet's interior and remain hidden from our sight — fortunately, scientists can utilize technology to understand and track them, reports PHYS.org.

In a new study, researchers from the University of Hawaii at Manoa analyzed a 200-year record of lava chemistry from Kilauea and Mauna Loa and discovered that the two most active volcanoes in Hawaii actually share a common magma source in the Hawaiian plume.

According to Aaron Pietruszka, the lead author of the study and an associate professor in the Department of Earth Sciences at the School of Ocean and Earth Science and Technology, it was previously believed that the different chemical compositions of lava from Kilauea and Mauna Loa required entirely separate magma pathways from each volcano's mantle source to the surface. However, the results of the latest research suggest that this assertion is incorrect. Melt from a common mantle source in the Hawaiian plume can be alternately transported to either Kilauea or Mauna Loa on a timescale of decades.

It is worth noting that Mauna Loa is considered the largest active volcano on the planet. Its most recent eruption occurred in 2022, following the longest period of inactivity, which lasted about 38 years. This pause in Mauna Loa's eruptions coincided with a significant 35-year eruption of neighboring Kilauea, which ended in 2018 with the collapse of the summit caldera, an unusually large rift eruption, and lava fountains reaching heights of up to 80 meters.

The study's authors believe that the long-term pattern of such contrasting eruption behaviors suggests that there is an actual magmatic connection between these volcanoes. This magmatic link between Kilauea and Mauna Loa leads to a broad correlation between changes in the chemical composition of their lavas.

Pietruszka stated that he and his colleagues found that in the late 19th century, Mauna Loa was more active while Kilauea remained less active, and the lava chemistry from Kilauea became more "unique" and specific to compositions observed only in Kilauea. The scientists believe this was caused by the transfer of mantle-derived melt from the common magma source to Mauna Loa.

The record shows that from the mid-20th century until 2010, the opposite occurred: Mauna Loa became less active, while Kilauea became incredibly active. During this time, the lava chemistry from Kilauea began to resemble that of typical lava from Mauna Loa.

Pietruszka noted that he and his colleagues concluded that this was due to a change in the transfer of mantle-derived melt from the common source in the Hawaiian plume from Mauna Loa to Kilauea. In simple terms, from time to time, each volcano becomes more active when it receives melt from the common mantle source. The results also indicate that this process causes measurable changes in lava chemistry.

Since 2010, the research group has been observing changes in the lava chemistry at Kilauea. This shift suggests that melt from the common source is now being redirected from Kilauea to Mauna Loa for the first time since the mid-20th century.