Examples of the mightiest energy releases by great earthquakes and volcanic eruptions and hypotheses providing explanations for them are analyzed along with the results of some recently published researches and visualizations.The emerging conclusions are that the mechanism of the strong earthquake is a chemical explosion;that volcanic eruption is a special type of earthquake wherein the hypocenter rises to the earth-surface;and that there is an association between the seismic-volcanic processes and mantle “fluids” and the lack of energy for mantle plumes.A conceptual system of hypotheses is put forward to explain the conservation of energy during Earth’s accretion,its quasi-stable release by primordial H- and He-degassing and of the crucial role of the energy of degassing-comprisingreactions in endogenic processes.Specific mechanisms and chemical processes are proposed for the gas-liquid mantle plumes melting through the solid mantle using heat-energy released in reactions of their metamorphic and chemical transformation under gradual decrease of pressure and temperature;volcanic gases are put forward as energy carriers.He performance as a unique measuring transformer correlative to the internal heat flow was used for calculation of energy release by degassing;it equals to 5.12×10~(20) J/yr.an amount of energy five-fold greater than the entire energy loss involved in earthquake and volcanic activity.The hypotheses proposed are objectively testable. Examples of the mightiest energy releases by great earthquakes and volcanic eruptions and hypotheses providing explanations for them are analyzed along with the results of some recently published researches and visualizations. The emerging conclusions are that the mechanism of the strong earthquake is a chemical explosion; that volcanic eruption is a special type of earthquake where the hypocenter rises to the earth-surface; and that there is an association between the seismic-volcanic processes and mantle “fluids ” and the lack of energy for mantle plumes. A conceptual system of hypotheses is put forward to explain the conservation of energy during Earth’s accretion, its quasi-stable release by primordial H- and He-degassing and of the crucial role of the energy of degassing-comprising reactions in endogenic processes. Special mechanisms and chemical processes are proposed for the gas-liquid mantle plumes melting through the solid mantle using heat-energy released in reactions of their m etamorphic and chemical transformation under gradual decrease of pressure and temperature; volcanic gases are put forward as energy carriers. He performance as a unique measuring transformer correlative to the internal heat flow was used for calculation of energy release by degassing; it equals to 5.12 × 10 ~ (20) J / yr.an amount of energy five-fold greater than the entire energy loss involved in earthquake and volcanic activity. The hypotheses proposed are objectively testable.