Stronger earthquakes closer to the surface and gas
explosions

Aftershocks are sometimes just as hazardous as the main quake itself. In fact, aftershocks may be so strong that they're stronger than the main quake. ... While foreshocks occur around the same time of the main quake, aftershocks may not occur until days or weeks later! The point at the Earth's surface directly above the focus is called the epicenter of the earthquake. At the epicenter, the strongest shaking occurs during an earthquake.

Hope this helps, have a great day/night, and stay safe!

a and b

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.