Volcanoes
The Tungurahua's volcanic activity follows last month's eruption, when a column of gas shot up seven kilometers into the sky.
No casualties have been recorded so far, but flight re-direction is being considered.
Tungurahua is located approximately 150 kilometers southeast of Ecuador's capital, Quito.
After a long period of peaceful resting, the volcano erupted in 1999, leading to the evacuation of about 250,000 people.
In 2006, Tungurahua underwent another major eruption, leading to the death of seven villagers. Yet another major eruption took place in 2008, leading to more evacuations. The next eruptions occurred in May and in November 2010.
The National Disaster Risk Reduction and Management Council (NDRRMC) also reported weak emission of white steam from the volcano's northwest thermal vents.
"For the past 24-hour observation period, Bulusan Volcano's seismic network detected nine volcanic quakes. Measurement of sulfur dioxide emission rate yielded an average value of 36.56 tons per day. Weak emission of white steam was observed from the northwest thermal vents from 8:35 to 10:35 a.m. (Monday)," the NDRRMC said in its 8 a.m. bulletin.

Mount Bromo spews volcanic material as it erupts in this aerial shot taken from an Indonesian Air Force airplane that flew over Probolinggo, East Java, Indonesia on Monday, Nov. 29, 2010.
Officials say civilian flights to and from Abdurahman Saleh Airport in East Java Province will remain grounded for at least five days. Tourists were not allowed to visit Mount Bromo on Friday.
Volcanic eruption from this mountain killed two tourists in 2004.
Indonesia is home to about 130 active volcanoes.
This follows the deaths of hundreds of people after Mount Merapi started its volcanic activities in late October.
Indonesia straddles the Pacific Ring of Fire - and lately, this nation of islands has been living up to the region's fiery reputation. A number of so-called minor ash explosions from Mount Bromo on Sunday (Nov. 28) caused a nearby airport to close as scientists upgraded the volcano to its highest alert level, according to the Indian newspaper The Hindu. On the same island, Java, Mount Merapi's recent eruptions killed hundreds and prompted mass evacuations.
The eruption watch also continues in the straight just west of Java where Anak Krakatau has also been increasingly active lately.
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The heightened eruption alerts come just a couple weeks after Mount Merapi's relentless erupting killed more than 300 people.
Mount Merapi's devastation has been estimated at $611 million and pyroclastic flows have destroyed huge swaths of forest (and one unfortunately placed golf course), according to the People's Daily Online.
In its latest bulletin, Phivolcs said that the quake occurred at around 7:27 p.m. and lasted for about 11 minutes. Clouds, however, prevented state volcanologists to visually observe it.
The statement did not say what distinguished an "explosion-type" earthquake from any other volcanic tremor.
Sulfur dioxide emission rate was measured at 13 tons per day.
About 11 volcanic quakes were also recorded by the seismic network around the volcano during the past 24-hour observation period.
Phivolcs said Bulusan's status remained at alert level 1 and the public was reminded not to venture into the four-kilometer permanent danger zone as sudden steam and ash explosions may occur.
Earlier this week the government raised the alert level at Mount Bromo to its highest level, telling villagers and tourists to stay off the rumbling slopes.
Government volcanologist Agus Budiono says the mountain, a popular tourist attraction, spewed ash more than 1,600 feet (500 meters) in the air Friday.
Mount Bromo typically erupts about once a year but unlike nearby Mount Merapi rarely spits debris and hot gas far from its crater. However, two people were killed in a 2004 eruption.

A man stands in his destroyed village after the eruption of Mount Merapi in Klaten, Indonesia, on Friday. In addition to those killed immediately in the disaster, people have died from burns they sustained, officials say.
The volcano, located in the middle of the central Indonesian island of Java, initially erupted Oct. 26 - less than 24 hours after a tsunami slammed into the remote Mentawai islands at the western end of the country, killing 509 people.

This aerial view taken on Tuesday shows the Mount Merapi volcano erupting in Indonesia's central Java province.
Mount Merapi shot out more hot clouds Friday evening, though no new deaths were reported from those flows, which slid as far as 10 kilometres from the crater. The mountain has continuously spewed ash - and occasionally torrents of rock, gas and lava in dramatic eruptions - since it roared to life Oct. 26 after years of dormancy.
The volcano is the most active in Indonesia, a vast archipelago of 235 million people that is prone to seismic activity because it sits along the Pacific "Ring of Fire," a horseshoe-shaped string of faults that lines the Pacific Ocean.
One of the country's 23 active volcanoes, Bulusan came back to life last weekend after emitting lava three years ago.
The state institute of volcanology says its analysis of the ashfall, which has blanketed about six municipalities, showed it contains no magma and there is no danger of eruption.
The latest blast early Friday shot up ash and steam some 500m above the 1,560m summit.
Authorities have distributed face masks, opened up evacuation centers and warned aircraft to avoid flying near the volcano.
The news comes as the frequency of eruptions of the volcano increases.
On Friday there were 615 eruptions, on Saturday there were 623 and on Sunday 668.
Anton S. Pambudi, a Banten province official who monitors the volcano, said the latest eruptions had changed the shape of the crater and his team would continue to monitor it.
Banten Governor Ratu Atut Chosiyah said Anak Krakatau (Child of Krakatau) did not pose a threat and the eruptions, which can be seen from the western tip of Java, were spectacular to watch.
Krakatoa exploded in 1883, with the resulting tsunamis killing an estimated 40,000 people, though some estimates put the death toll much higher.
The explosion is still considered to be the loudest sound ever heard in modern history, with reports of it being heard nearly 4,800 kilometers away.









