People living in the northern Leeward Islands must have been wondering last week what they had to do to get a break. At one point early in the week, they were dealing with an earthquake, an active volcano and an approaching tropical storm, all at the same time.

These islands are on the edge of the Puerto Rico Trench, one of the deepest parts of the Atlantic Ocean.

The Trench is 560 miles long and more than five miles deep at its lowest point. It curves outside the Leeward and Windward Islands to Venezuela, marking the line where the Caribbean Plate, a small chip of the earth’s crust, runs into the North American Plate.

All along this edge, the Caribbean Plate has pushed the North American plate down, and the conflict as the plates move creates earthquake hot spots. The Caribbean Plate is moving at a top speed of less than an inch a year, but when friction stops a section of the edge from moving, a lot of momentum builds up. Sooner or later, the “stuck” spot lets go, and the released energy shakes everything around it.

This is a very active region, with three live volcanoes and hundreds of earthquakes every year, though most of the quakes are too small to feel. The week of October 3-10 was relatively quiet – the U.S. Geological Survey reported only 25 quakes in the region. The one that shook Anguilla and St. Martin around lunchtime on Monday, October 5, measured just 4.5 on the Richter scale – big enough to feel, but not to cause serious damage.

Even so, it scared people out of their homes and workplaces. Some typical comments: “It was like a freight train going through the house in Cole Bay, was a slight tremor in Simpson Bay, then another large aftershock and then power was out.” and “Wow, serious one too, in a split second I thought the windows were going to fall out.” According to reports, a window of a Bush Road furniture business did fall out.

On Montserrat, south of the quake, the Soufrière Hills volcano started waking up on October 4. It rumbled through the morning, then started throwing up plumes of ash and steam. This belching continued through the week, accompanied by small rock falls and flows of hot mud. Some of the plumes reached 20,000 feet into the sky. The ash cloud has spread north across Puerto Rico and as far south as Curaçao. (Volcanic ash is a filthy nuisance and a health hazard in the city, but in the countryside it can add much-needed fertility to the soil.)

Meanwhile, Tropical Storm Henri was bearing down on the northern Leewards – a lot to deal with on top of the volcano and the earthquake. However, wind shear and Sahara dust pulled the weak storm apart before it reached land. That’s been happening a lot this year, but it’s no reason to feel safe. We live in a part of the world where earthquakes and hurricanes are facts of life, and it only takes one to do serious damage to life and property. A little preparation now can save a whole lot of grief later.

Is a below average hurricane season a totally good thing? More on that next week.