According to the mantle plume theory what causes hot spots?

According to the mantle plume theory, Plumes are proposed to ascend through the mantle and start to incompletely dissolve on arriving at shallow profundities in the asthenosphere by loose melting.

It leads to enormous volumes of volcanic eruption. The plumes hypothesis suggested that this dissolved magma ascends to the surface and emits to shape "hot spot". the plume head liquefies partially on arriving at shallow profundities, a plume is frequently invoked as the reason for the hotspots at particular region, for example, Hawaii or Iceland.

feral cats are estimated to eat tens of millions of native animals each night in australia

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.