What causes stress accumulation at a seismic gap?

Stress accumulation at a seismic gap is primarily influenced by low friction among rocks, which can inhibit movement along a fault line. When friction is low, the rocks on either side of a fault can become "locked" together even as tectonic forces continue to apply stress. This situation leads to the gradual buildup of strain in the rocks. When the accumulated stress exceeds the frictional resistance, it can result in a sudden release of energy, manifesting as an earthquake.

The other factors, while relevant to seismic activity, do not directly contribute to stress accumulation in the same way. High seismic activity might suggest that faults are active and releasing stress. Constant fluid extraction could reduce pressure within fault zones but is not a primary mechanism for stress accumulation at seismic gaps. Tectonic shifts lead to the overall movement and interaction of faults but do not specifically describe the conditions that create stress at a particular seismic gap.