No, volcanic eruptions and earthquakes do not occur only at plate boundaries. While the majority of these events do happen at boundaries, they can also occur within plates, known as intraplate activity.

Here's why:

Plate Boundaries:

* Divergent boundaries: Where plates move apart, magma rises from the mantle to create new crust. This results in volcanic activity and shallow earthquakes.

* Convergent boundaries: Where plates collide, one plate may subduct beneath the other, causing melting and magma generation. This leads to volcanic arcs and deep earthquakes.

* Transform boundaries: Where plates slide past each other, friction creates stress and causes earthquakes.

Intraplate Activity:

* Hotspots: These are areas within a plate where plumes of hot magma rise from deep within the mantle. These plumes create volcanic chains and can cause earthquakes. Examples include the Hawaiian Islands and Yellowstone National Park.

* Stress and Strain: Even within plates, stresses can build up over time due to plate movements, leading to earthquakes. These earthquakes are typically smaller in magnitude than those at plate boundaries.

In Summary:

While plate boundaries are the most common locations for volcanic eruptions and earthquakes, these events can also occur within plates due to hotspots and the buildup of stress.