The shock of the past few days in Nepal gave way to despair, frustration and a few larger questions on Tuesday, as the death toll from the devastating earthquake that wracked the small Himalayan nation over the weekend rose above 4,000 — a number that will almost certainly rise once international rescue teams reach rubble-filled outlying areas surrounding the capital, Kathmandu. The massive quake, measuring 7.8 on the Richter scale and followed by three days of panic-inducing aftershocks, has left the country — already one of the world’s poorest and least developed — reeling and utterly helpless. But while the earthquake is tragic, seismologists said it didn’t come as a surprise.