what type of activity is indicating that mauna loa may be entering a new period of volcanic activity
Kīlauea A prominent structure on Kīlauea's southern flank is the Hilina fault system, a highly active fault moving vertically an average of 2 to 20 mm (0.1 to 0.8 in) per year along the system. Its physiographic province is 500 m (1,640 ft) deep, but it is unknown if it is a shallow listric fault or if it penetrates to the very base of the volcano.[3] A number of cinder cones, satellite shields, lava tubes, and other eruptive structures also dot the volcano, evidence of its recent activity.[20] Kīlauea has some interactions with Mauna Loa, its larger neighbor and only other recently active volcano on the island; interspersed lava flows and ash deposits belonging to its neighbor have been found on its flanks, and some of Mauna Loa's flows are, in turn, blanketed in Kīlauea tephra. In particular, the saddle between the two volcanoes is currently depressed, and is likely to fill over in the future.[17]
Hawaii hotspot Wilson proposed that mantle convection produces small, hot buoyant upwellings under the Earth's surface; these thermally active mantle plumes supply magma which in turn sustains long-lasting volcanic activity. This "mid-plate" volcanism builds peaks that rise from relatively featureless sea floor, initially as seamounts and later as fully-fledged volcanic islands. The local tectonic plate (in the case of the Hawaii hotspot, the Pacific Plate) slowly slides over the hotspot, carrying its volcanoes with it without affecting the plume. Over hundreds of thousands of years, the magma supply for the volcano is slowly cut off, eventually going extinct. No longer active enough to overpower erosion, the volcano slowly sinks beneath the waves, becoming a seamount once again. As the cycle continues, a new volcanic center manifests, and a volcanic island arises anew. The process continues until the mantle plume itself collapses.[1]