A Moment: Vanuatu Seismicity: Ground Flow

By Paul D. Miller aka Dj Spooky

A moment, a date: Tuesday, August 10, 2010. It’s not every day that you have a moment where you land in the middle of an earthquake, but that’s exactly what happened to me. Imagine when a flight lands. If everything is as it should be, you usually get some rough and tumble bounce-roll motion. The plane’s shock absorbers do their thing, and the kinetic motion of the aircraft’s collision with the tarmac is transmitted from the wheels of the plane straight through to your body, and the movement of the plane from air to ground is gracefully arrested. I fly a lot, and I’m always in the suspended place between movement and stillness when the plane lands .If you’re in a flight that is landing, one of the first things that goes through your mind is a sense of relief when the wheels touch the ground.
This didn’t happen on Tuesday, August 10, 2010. The plane landed after a 5-hour flight from New Zealand to Port Villa, the capital of Vanuatu, part of an 83-island archipelago in the middle of the South Pacific’s “Ring of Fire” – a region of the world where several tectonic plates meet. This makes for a lot of earthquakes and land tremors above and below the oceanline. We also happened to land in the middle of a 7.5 magnitude earthquake. A situation that etched itself into my memory.

Everything suspends in an earthquake – time becomes elastic, electricity turns on and off, and all aspects of modern life grind to an eerie halt. In a generic sense, the word “earthquake” describes any “seismic event” – whether a natural phenomenon, or one caused by humans—that generates seismic waves. Earthquakes are metaphors made into physical fact. Metaphors are ways of framing an experience, defining a situation, and like other kinds of social human behavior that are “metaphorical,” sometimes when facts “on the ground” become the actual space of an event, that’s when you really know that you are in a moment. You inhabit the space-time of the scenario. Earthquakes are generated by phenomena that mostly relay a checklist of collisions: they’re caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine explosions, underground nuclear tests. An earthquake’s point of initial rupture is called its focus or “hypocenter.” The term epicenter refers to the point at ground level directly above the hypocenter. Sometimes, that’s how you can think of change in a human context too. The moment an earthquake occurs, you trace the after effects through concentric time lapsed feedback, mechanisms, kind of like watching a stone drop onto the surface of a pond, but what ripples is earth, not water. The usual way of thinking about an earthquake is to put a spin on the scene: the result of a sudden energy release in the Earth’s crust that creates seismic waves. This seismicity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. The moment magnitude (or the related and mostly obsolete Richter magnitude) of an earthquake is conventionally reported, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale. That’s the way we do things these days. Richter Scale is so 20th century.

When I landed, the ground and the plane entered a complex dance. The plane’s body trembled, creating frisson that sent shockwaves through my body. No one on the Air Vanuatu Flight NF 0053, stood up. An announcement was played over the speakers, telling us something to the effect that our flight had landed in the middle of a highly irregular situation. A major 7.5 magnitude earthquake struck Vanuatu on Tuesday, August 10, 2010, producing a small tsunami and sending thousands of anxious people running for the island’s hills. The underwater quake, 35 kilometers (22 miles) deep and merely 40 kilometers from Port Vila, shook buildings in the city for about 15 seconds, but did not cause vital damage. The guests of foreign hotels and some residents raced to higher ground in case of tsunami, locals said, and police sounded sirens to inform people to abandon homes and to get out into the open. We were stuck on the plane because the airport was considered unsound. The ground moved, and moved again. The plane rested on the tarmac, and we watched the airport sway with the ground tremors that rippled beneath our feet. Our captain mentioned that the Pacific Tsunami Warning Center announced that a 23-centimetre (9.2 inches) tsunami struck Port Vila, and he warned us that bigger waves could be seen in further areas. By way of our captain, the Pacific Center said that “Higher wave amplitudes may yet be observed along coasts near the earthquake epicenter”. As I sat in the seat with world rippling around me, the South Pacific did a graceful ballet with all the aspects of civilization that I take for granted: watching buildings sway with the palm trees, the plane ebbing-flowing on the tarmac, and the water near the airport ripple with a power far beyond the movement of the waves. That’s when I really felt the metaphor of the moment. I felt like a leaf in a pond, dancing to the rhythms of the planet. That was my moment. Suspended, floating on the ocean of the Earth, the logic of our civilization turned to flotsam and jetsam. The airport, the plane, the runway, all spoke a language that the earthquake didn’t. I liked that.