Mt Mayon Menacingly Mute – Update [3 January 2010]

Will Mayon Erupt Again Soon?

Which scenario will Mayon adopt: Chaitén, Kilauea, Galeras, or one with an entirely different pattern?

What seems highly probable—judging by a number of factors including increased tempo and rhythm of volcanism globally—is that Mayon won’t be in repose for very long.

Mayon activity highlights during  the past 24 hours:

• Volcano hazard alert down to level 3
• 9 volcanic earthquakes detected
• 30 rockfall events
• No steam emissions
• Summit crater covered by heavy clouds for most of the 24-hr observation period.
• Faint glow at the crater occurred
• Sulfur Dioxide emission rate reported at an average rate of 2,094 tons per day

Mayon Volcano Bulletin 21 released by PHIVOLCS on 3 January 2010

Mayon Volcano’s (13.2576 N, 123.6856 E) seismic monitoring network  detected 9 volcanic earthquakes and 30 rockfall events related to the detachment of lava fragments at the volcano’s upper slopes during the past 24- hour observation period. Steaming activity was not observed due to thick clouds that covered the summit crater. Pale crater glow was observed last night. Sulfur Dioxide (SO2) emission rate was measured yesterday  morning at an average value of 2,094 tonnes/day.

Alert Level 3 is in effect over Mayon, which means that the 6-km radius Permanent Danger Zone around the volcano and the 7-km Extended Danger Zone on the southeast flank of the volcano should be free from human activity because of sudden explosions that may generate hazardous volcanic flows. People residing close to these danger areas are also advised to observe precautions associated with post-eruption activity, such as rockfalls, pyroclastic flows, and ash fallout which can also occur anytime due to instabilities of lava deposited on steep slopes. Active river channels and those perennially identified as lahar prone in the southern sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall. Civil aviation authorities must advise pilots to avoid flying close to the volcano’s summit as ejected ash and volcanic fragments from sudden explosions may pose hazards to aircrafts. PHIVOLCS-DOST is closely monitoring Mayon Volcano’s activity and any new significant development will be immediately posted to all concerned.

For previous entries, additional information, photos and links to Mayon Volcano see links below:

• Mayon may be gradually returning to the repose period
• Could Blue Moon Trigger Mayon Explosion?

Related Links:

• Mayon Volcano Links Page [Recent Posts, Photos, Videos and Comments]
  
• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Mayon Volcano Update [2 January 2010]

Philippines experts out of step with Mayon?

Mayon may be gradually returning to the repose period: Phivolcs

The information coming out of PHIVOLCS and the decisions made by the state volcanologists concerning the volcano’s hazard status are at best inconsistent with the history of Mayon’s eruptive activity.

Highlights from the news, eye-witness accounts, official and unofficial reports on Mayon’s status during  the past 24 hours:

• Phivolcs is lowering Mayon’s alert status from level 4 to level 3 [hazardous explosive eruption less likely]
• Volcanic quakes down to 13 events (majority of events associated with rockfalls, and rolling  of lava fragments down the mountain)
• No tephratic eruptions for the 3rd day
• Sulfur Dioxide emission rate of 2,621 tons per day up (more than twice the amount previous day), but down from a high of about 9,000 tons.
• Small amount of steam emitted

Mayon Volcano Bulletin 20 released by PHIVOLCS on 2 January 2010

The seismic monitoring network around Mayon Volcano (13.2576 N, 123.6856 E) detected 13 volcanic earthquakes and 68 rockfall events related to the detachment of lava fragments at the volcano’s upper slopes during the past observation period. Emission of weak volume of white steam at the summit crater was observed during cloud breaks yesterday. Sulfur Dioxide (SO2) emission rate was measured yesterday morning at an average value of 2,621 tonnes/day.

The latest activity of Mayon still indicates that its overall state of unrest remains relatively high.  However, this phase of unrest, characterized by moderate seismicity, high volcanic gas outputs and continuing glow of the summit are processes normally associated with very gradual return to the repose period.  The volcanic system is expected to continue producing earthquakes and to vent a large amount of gases because fresh magma still resides along the whole length of the volcanic pipe and near the summit.

From 28 December to present, a declining trend in Mayon volcano’s activity was noted as reflected by the following observations:

1.      No ash ejections were observed since 29 December. Steam emission was most of the time weak and white in color indicating considerable decrease in energy and absence of ash.

2.      Majority of the type of earthquakes that were recorded during the past days were associated with rockfalls and rolling down of fragments from the lava deposits along Bonga gully and the advancing lava front.

3.      Measured SO2 levels have also showed a decreasing trend from a maximum of 8,993 tons per day to 2,621 tons per day. The still high concentration of SO2 gas emission suggests that there is residual magma degassing at shallow depth.

In view of the above observations, PHIVOLCS-DOST is lowering the alert status of Mayon from Alert Level 4 to Alert Level 3 to reflect the overall gradual decrease of activity. Alert Level 3 means that there is less probability of a hazardous explosive eruption.  However, the lowering of the alert level from 4 to 3 should not be interpreted that the unrest of the volcano has ceased. If there is resurgence in the volcano’s activity and the potential for explosive eruptions is perceived to be forthcoming, the alert level may be raised back to 4 but if there is noticeable downward trend in the monitored parameters, then the alert will be further lowered to Alert Level 2.

For previous entries, additional information, photos and links to Mayon Volcano see links below:

• Could Blue Moon Trigger Mayon Explosion?

• Mayon Pipes Down, for Now

• Mayon Calmer, But it Could Be the Lull Before the Storm

• The Raging Lava Mill

Related Links:

• Mayon Volcano Links Page [Recent Posts, Photos, Videos and Comments]
  
• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Mayon Volcano Update [1 January 2010]

Could Blue Moon Trigger Mayon Explosion?

State vulcanologists believe full moon could trigger Mayon explosion

Resident volcanologists at Phivolcs said a major eruption could occur based on the volcano’s behavior and the the full moon working as triggering mechanism to cause the restive volcano to explode.

According to their theory,  the gravitational pull of the full moon as it gets closer to Earth could cause a large increase in the rate of ascent of magma up and out of the volcano.

The Moon glows by light it reflects from the Sun and is frequently the brightest object in the night sky. The Moon orbits the Earth about once a month (moon-th) from about 1 light second away. The above-pictured Full Moon occurs when the Moon is nearly opposite to the Sun in its orbit.   Credit: Lick Observatory.

How They Paint the Moon Blue

Most years have twelve full moons occurring monthly; however, each solar calendar year has an additional eleven days compared with the lunar year. The extra days add up to a 13th full moon called a “blue moon” about 7 times in the 19-year Metonic cycle, which translates into one blue moon every two or three years.

Other highlights from the news, eye-witness accounts, official and unofficial reports on Mayon’s status during  the past 24 hours:

• 28 volcanic earthquakes recorded
• 91 rockfall events
• Some steam emitted
• Lava still flowing
• SO2 emissions down to daily average of 1,255 tons
• Phivolcs may lower alert level from 4 to 3, if no significant events occur in the next few days

Human Angle:

• A power blackout was enforced in the danger zone around Mt Mayon on Thursday, to discourage residents from returning to their homes.
• The water supply is due to be turned off Friday, as state volcanologists warned that the full moon  could trigger a major explosion today.
• A military spokesman said many residents were using  “backdoor” routes to return to their homes for the New Year’s festivities.
• About two dozen tourists were reportedly arrested as they entered the danger zone.
• Local police and military have been ordered to carry out house-to-house searches and arrest any residents that might still be in the danger zone.
• Aid organizations are plan to evacuate about 4,000 animals to areas outside Mayon danger zone, ABC said.

Mayon Volcano Bulletin 19 released by PHIVOLCS on 1 January 2010

The seismic monitoring network around the volcano detected 28 volcanic earthquakes and 91 rockfall events related to the detachment of lava fragments at the volcano’s upper slopes during the past 24-hour observation period. No ash explosion was observed. Weak to moderate emission of white steam at the summit crater was seen during cloud breaks from 7:29 AM – 8:30 AM and from 5:25 PM to 5:40 PM yesterday. Flowing lava and intermittent rolling incandescent lava fragments were observed last night. Sulfur Dioxide (SO2) emission rate was measured at an average of 1,255 tons/day.

Alert Level 4 is still being maintained but if no significant events should occur during the next few days, PHIVOLCS-DOST shall consider the possibility of lowering down the alert level from 4 to 3. PHIVOLCS-DOST still strongly reiterates that the Extended Danger Zone (EDZ) from the summit of 8-km on the southern sector of the volcano and 7-km on the northern sector should be free from human activity. Active river channels and those perennially identified as lahar prone in the southern sector should also be avoided especially during bad weather conditions or when there is heavy and prolonged rainfall. In addition, Civil Aviation Authorities must advise pilots to avoid flying close to the volcano’s summit as ejected ash and volcanic fragments from sudden explosions may pose hazards to aircrafts. PHIVOLCS-DOST is closely monitoring Mayon Volcano’s activity and any new significant development will be immediately posted to all concerned.

For previous entries, additional information, photos and links to Mayon Volcano see links below:

• Mayon Pipes Down, for Now

• Mayon Calmer, But it Could Be the Lull Before the Storm

• The Raging Lava Mill

Related Links:

• Mayon Volcano Links Page [Recent Posts, Photos, Videos and Comments]
  
• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links