PADANG, Indonesia (CNN) -- An international team of earthquake specialists says Indonesia faces another potential "giant" quake in the near future.
A worker constructs a wall to protect against tsunami waves in Lais, North Bengkulu, Saturday.
The scientists, including a team from the California Institute of Technology, says three major quakes in the last week have increased the likelihood of a major disaster.
CNN traveled to the earthquake zone with a scientist who deliberately puts himself in the path of the world's most powerful quakes.
"You'd see a strip 30 meters high, stripped down to bedrock," says John Galetzka, a former U.S. Army ranger who is now adventuring on another frontline as an earthquake geologist. He is investigating the fault line that sparked the 2004 tsunami and, in recent days, three more powerful quakes.
Last Friday, Galetzka shot video footage of the shaking beach, with startled locals scrambling upshore.
His thoughts turned immediately to the tsunami danger, and his command ship offshore. Just moments later he caught the panic near the beach, as he saw families evacuating to the hills about 200 meters behind their village.
The day before, another big quake struck -- larger, but further away. Galetzka recalls the long slow waves and a shivering water bottle. For the American geologist, this is where theory meets reality.
"I just felt like the luckiest man alive to feel two strong events," he says. "You can almost hear the excitement in my voice -- oh my gosh, this is it, this is it ..."
Galetzka is now examining the evidence that his team believes indicates the arrival another giant earthquake, and possible tsunami.
He has established a network of position-markers, linked by satellite, that show a constant creep, northeast, among the islands on Indonesia's Indian Ocean frontier. The first one was placed in August 2002.
The 30 measuring stations along Sumatra's western coast tell an ominous tale. Driven by the plate beneath the Indian Ocean, the entire coastline is flexing, as the earth literally bends. The pressures are already enormous, and at some point probably soon, they will become intolerable.
The implications are terrifying.
"Eventually it has got to release in (the form) of giant earthquake," states Galetzka matter-of-factly.
It could be a rare magnitude-9 quake, and with the plates so tightly sprung, it will happen sooner, he believes, rather than later.
Knowing what he knows, does he worry about the people living along this coast?
"I absolutely do," he replies. "I tell them to be prepared. Whenever I am in Padang I think about my escape routes, almost every moment."
As he criss-crosses around the islands, searching for data, Galetzka says his aim is to save lives. But he, more than anyone, knows the risks -- that one day he'll confront a giant wave, a tsunami powerful enough to swallow islands.
The geologist's voice quivers as he imagines "the big one."
"If we saw it, we'd just head right into it. I'd shake your hand and say, good luck!" E-mail to a friend