It began growing last November, steadily moving west and pushing rock and other debris out of its way as it goes. Mount St. Helens has been quietly erupting since a flurry of tiny earthquakes began in late September 2004. Scientists initially mistook the quakes as rainwater seeping into the hot interior of the older lava dome.

But it soon became clear that magma was on the move, confirmed by the emergence of fire-red lava between the old lava dome and the south crater rim a few weeks after the seismic activity began.

The volcano has continued pumping out lava ever since. Eventually, scientists expect the volcano will rebuild its conical peak that was obliterated in the May 18, 1980, eruption that killed 57 people.

The growth of the new lava dome has been accompanied by low seismicity rates, low emissions of steam and volcanic gases, and minor production of ash, the USGS said.

"Given the way things are going now, there's no hint of any sort of catastrophic eruptions," USGS geologist Tom Pierson said. "At any time, however, things can change."

Scientists flew a helicopter into the crater late last week to adjust equipment and take photographs that will likely be used to determine just how much the new lava dome has grown the last several months.

The latest quake, with its epicenter 137 kilometers (85 miles) east of Nuku'Alofa and at a depth of 37 kilometers, was recorded at 12:25 a.m. local time, the survey said in an e-mailed statement.

There were no reports of damage or injury. A magnitude 7.9 earthquake, the world's biggest in more than a year, struck near Tonga a day earlier, triggering tsunami warnings for New Zealand and Fiji that were later called off.

Scientists have yet to raise the threat level to the highest alert, which would require the immediate evacuation of villages on Merapi's fertile slopes and foothills. But the lava flows and burning around the crater suggest that pressure within the volcano is reaching a critical point. "The volcano has shown significantly more activity," said Subandriyo, the head of the local monitoring office.

An estimated 14,000 people live in Merapi's shadow, and most are still there, reluctant to abandon property and livestock. They plan to stay until forced to leave, or until nature sends them signals, such as lightning around the peak or animals moving down the slopes.

About 1,300 people have already been moved out of the danger zone, mainly women, children and the elderly. Local officials say that some are returning to their homes during the day to feed livestock.

The lava flows began as first a powerful under-sea earthquake measuring 6 on the Richter scale and then an aftershock hit the South Pacific islands of Tonga. But the earthquakes caused no damage.

They came a day after a larger quake in Tonga sparked a tsunami alert. The alert, issued by a monitoring centre in Hawaii, was lifted after two hours, but the incident exposed deficiencies in a system intended to prevent the devastating death toll of the Indian Ocean tsunami of 2004.

Tonga itself did not receive the warning because of a power failure, while in Fiji only people living on the main island were alerted; those on the other 110 islands remained unaware. In New Zealand, hundreds of people on the east coast fled their homes for higher ground after watching television reports, although no evacuation had been ordered.

Indonesian authorities are preparing to evacuate thousands of people as lava began flowing from the crater of the country's most active volcano.

Gunung Merapi, or Fiery Mountain, has been rumbling for weeks, with scientists on alert for an imminent eruption. Lava started pouring down its slopes early yesterday, but stopped a few miles from inhabited areas. Merapi is one of the most dangerous volcanoes in the Pacific "Ring of Fire", a series of fault lines stretching through Japan and south-east Asia. Seventy people died when it erupted in 1994. In 1930, an eruption claimed 1,300 lives.

Scientists have yet to raise the threat level to the highest alert, which would require the immediate evacuation of villages on Merapi's fertile slopes and foothills. But the lava flows and burning around the crater suggest that pressure within the volcano is reaching a critical point. "The volcano has shown significantly more activity," said Subandriyo, the head of the local monitoring office.

An estimated 14,000 people live in Merapi's shadow, and most are still there, reluctant to abandon property and livestock. They plan to stay until forced to leave, or until nature sends them signals, such as lightning around the peak or animals moving down the slopes.

About 1,300 people have already been moved out of the danger zone, mainly women, children and the elderly. Local officials say that some are returning to their homes during the day to feed livestock.

The lava flows began as first a powerful under-sea earthquake measuring 6 on the Richter scale and then an aftershock hit the South Pacific islands of Tonga. But the earthquakes caused no damage.

They came a day after a larger quake in Tonga sparked a tsunami alert. The alert, issued by a monitoring centre in Hawaii, was lifted after two hours, but the incident exposed deficiencies in a system intended to prevent the devastating death toll of the Indian Ocean tsunami of 2004.

Tonga itself did not receive the warning because of a power failure, while in Fiji only people living on the main island were alerted; those on the other 110 islands remained unaware. In New Zealand, hundreds of people on the east coast fled their homes for higher ground after watching television reports, although no evacuation had been ordered.