A new subduction zone forming off the coast of Portugal heralds the beginning of a cycle that will see the Atlantic Ocean close, as continental Europe moves closer to America. Published in Geology, new research led by Monash University geologists has detected the first evidence that a passive margin in the Atlantic Ocean is becoming active. Subduction zones, such as the one beginning near Iberia, are areas where one of the tectonic plates that cover Earth's surface dives beneath another plate into the mantle - the layer just below the crust. Lead author Dr João Duarte, from the School of Geosciences said the team mapped the ocean floor and found it was beginning to fracture, indicating tectonic activity around the apparently passive South West Iberia plate margin. "What we have detected is the very beginnings of an active margin - it's like an embryonic subduction zone," Dr Duarte said.

After 10 days of almost no activity, the volcano has woken up violently with 3 powerful explosions last night (at 22:05 and 23:58 UTC, ash plumes to 10-13,000 ft) and this morning at 04:26. The eruption this morning appears to be one of the largest explosions for a long time, producing an ash plume rising to 16-20,000 ft (5-6 km) altitude. An SO2 plume is also visible on satellite data.

Tokyo VAAC issued a warning of an ash plume drifting SE at flight level 200 (20,000 ft altitude), s. graphic.

As the Indonesian Volcanological Survey (VSI) specified in its latest bulletin, parts of the active lava dome of the volcano have recently (early June) grown higher than the northern crater rim, where it is cut by a valley extending to the northern feet of the stratovolcano. Therefore, potential continued growth of the dome poses the risk of rockfalls and pyroclastic flows reach the northern flanks, where a number of villages are located, namely Pasilulu and Talen. In addition, VSI scientists have detected an increase of seismicity and degassing since early May. This includes volcanic tremor from growing lava dome and deeper earthquakes, possibly related to new magma rising, and the occurrence of notable sulfur smell.

Ibu's activity has been characterized by the slow building of a new lava dome inside the breached summit crater since 1999. While present growth rate is still slow, and no or little incandescence is observed at the moment, the new seismic activity could herald a phase of more vigorous activity in the near future. In that scenario, the occurrence of dangerous landslides and pyroclastic flows would be likely and the northern slopes of the volcano should be considered a high risk zone. - Volcano Discovery

A weak eruptive activity has started from the volcano. Since last night, weak ash emissions have appeared from the central cone of the caldera of the volcano. The new activity is accompanied by a persistent steam plume and increasing volcanic tremor. So far there seem to be no lava flows or other significant eruptive processes. The new ash emissions are very diluted and reach about 200-300 m height. They were first observed on the Aviation camera of Perryville from last night at around 17-18h local time. AVO who has not yet reported about the ash confirmed to Blog Culture Volcan that the plume indeed contains very small amounts of ash, which pose no problems to aviation (for now). The volcano last erupted in 2008. - Volcano Discovery

Eleven years after an eruption of Mount Nyiragongo devastated the sprawling lakeside city of Goma, killing hundreds of people, eastern Congo's armed conflict is preventing scientists from predicting the volcano's next deadly explosion. With its plume of ash and steam reaching high into the sky, the brooding Nyiragongo is one of the world's most active volcanoes and a constant menace to the city of 1 million people, whose streets are still scarred by solidified lava. Attempts to monitor the volcano's activity have been dangerously curtailed by the M23 rebel group which has controlled its lush, forested slopes for the past year. Observation equipment has been looted by armed groups and the area around Nyiragongo is off-limits as rebel fighters defend their strategic positions overlooking Goma.
"What happened in 2002 will happen again. We just don't know when," Celestin Kasereka Mahinda, a volcanologist at the Goma observatory and head of a national committee charged with planning for natural disasters. Kasereka and his colleagues gave two months' warning before the last eruption but authorities ignored them. People only began to evacuate as the first fingers of lava probed their way into the town's densely populated residential areas. Goma's airport is still surrounded by lava blocs as big as cars, excavated after the runway was swallowed by molten rock. Kasereka used to conduct weekly checks on Nyiragongo, one of only three volcanoes in the world to have a permanent lava lake. "Surveillance is very reduced so the risk has become very big," he said.

The earthquakes experienced today in Carmen town, North Cotabato and the rest of Mindanao will possibly last for weeks or months. This was according to Jenila de Ocampo, Officer-in-charge of the Davao Seismic Station of the Philippine Institute of Volcanology and Seismology (Phivolcs), in a phone interview. She added the intensity might either be "felt" or "unfelt" by humans. On Monday morning, two strong quakes struck Carmen. A 5.7 magnitude was felt at 4:08 AM with epicenter at seven Kilometers (Km) Northeast of the town. It has a depth of 10 Km. The town was placed under Intensity VI. "An Intensity VI in the PEIS (Phivolcs Earthquake Intensity Scale) means there will be a minimal damage to poorly built structures, or those with light materials and even concrete structures which do not meet building standards like the proper placement of steel bars," De Ocampo explained.
At 7:31 AM, another quake jolted Carmen town. A 4.0 magnitude was recorded with epicenter at 7 Km Northeast of the town. It has a depth of 3 Km. Intensity II was felt in Matalam town, North Cotabato. On Saturday evening, a 5.7 magnitude earthquake rocked the town which hurt 5 people, damaged 60 houses in Kimadsil village alone, and destroyed a bridge as well as agricultural facilities, school buildings and health centers. The said quake, according to De Ocampo, "is shallow and tectonic in origin." Its depth was at 5 Km. "Strong earthquakes which are tectonic will cause aftershocks until the energy dissipates. In the case of Carmen which was hit by shallow quakes, the energy of the quake has little chance to dissipate when it reaches the surface," she said.

Explosive activity at Vanuatu's Mt Yasur volcano has increased in recent days.

According to observations by the Vanuatu Meteorology and Geohazards department, the activity level of the volcano on Tanna island is still at alert level 2 but an increase to 3 in the near future is possible.

In Alaska, scores of volcanoes and strange lava flows have escaped scrutiny for decades, shrouded by lush forests and hidden under bobbing coastlines.

In the past three years, 12 new volcanoes have been discovered in Southeast Alaska, and 25 known volcanic vents and lava flows re-evaluated, thanks to dogged work by geologists with the U.S. Geological Survey (USGS) and the U.S. Forest Service. Sprinkled across hundreds of islands and fjords, most of the volcanic piles are tiny cones compared to the super-duper stratovolcanoes that parade off to the west, in the Aleutian Range.

But the Southeast's volcanoes are in a class by themselves, the researchers found. A chemical signature in the lava flows links them to a massive volcanic field in Canada. Unusual patterns in the lava also point to eruptions under, over and alongside glaciers, which could help scientists pinpoint the size of Alaska's mountain glaciers during past climate swings.

"It's giving us this serendipitous window on the history of climate in Southeast Alaska for the last 1 million years," said Susan Karl, a research geologist with the USGS in Anchorage and the project's leader.

The Institute of Vulcanology warned that the eruption could intensify with ash rising as high as 1000 to 2000 metres, posing a threat to air traffic at Guatemala's international airport.

"Ash could spread over Guatemala City due to the direction of the wind," the country's disaster response office said in a statement.

The last major eruption of Pacaya, in May 2010, claimed the life of a television journalist, drove thousands of people from their homes and forced the closure of the Guatemala City airport for five days.

The 2552 metre-high Pacaya is 50 kilometres south of the capital and one of three active volcanoes in Guatemala.