El Hierro Island Experiencing Intense Seismicity, Inflation

El Hierro moving east, experiencing uplift amid intense seismic activity

Intense seismicity and inflation at El Hierro suggest magma is intruding underneath the tiny volcanic island, the smallest of Canary Islands, located  in the Atlantic Ocean off the coast of Africa (population ~ 10,000).

• Sharp increase in seismic activity in and around the tiny island (Area: ~ 278 km²) began on March 18, with the largest quake measuring 4.7 on Richter scale, which occurred on Friday.
• The majority of tremors are occurring at a depth of between 12 and 15 km.
• The latest geological activities have caused the island to move east and forced the ground to rise by 11 cm at Punta de Orchilla on the western tip of the island.

Map of El Hierro with recent quake epicenters

Image Credit: AVCAN. AVCAN.ORG was developed by Victor Tapia. Original idea, administration and all rights by Fernando Raja

Histogram of the recent earthquakes at El Hierro 18 -31 March, 2013. Note sharp increase in seismic activity since March 18, 2013. Image credit: AVCAN.

Latest Earthquake at El Hierro. Image credit: AVCAN.

Global Volcano Watch (Source: AVO; HVO; GVP)

New Activity/Unrest:

• Fuego, Guatemala (Lava fountains rising to 400 m above the crater reported on 20 March, causing 1.5 km long lava stream in the Ceniza drainage).
• Hekla, Southern Iceland
• Tungurahua, Ecuador

Ongoing Activity:

U.S. Volcanoes

• Kilauea, Hawaii  (Hawaii) – Code ORANGE – WATCH
• Cleveland Volcano (Alaska) – Code YELLOW – ADVISORY

Kamchatka Peninsula

• Gorely – Code YELLOW
• Karymsky, Eastern Kamchatka (Russia) – Code ORANGE
• Kizimen, Eastern Kamchatka (Russia) –  Code ORANGE
• Tolbachik, Central Kamchatka (Russia)  Code ORANGE
• Bezymianny – Code YELLOW
• Sheveluch Central Kamchatka (Russia) – Code ORANGE

Indonesia

• Batu Tara, Komba Island (Indonesia)
• Lokon-Empung, Sulawesi
• Paluweh, Lesser Sunda Islands (Indonesia)

Kurile Islands

• Snow – Code YELLOW
• Ivan Grozny – Code YELLOW

Other Volcanoes

• Bagana, Bougainville (PNG)
• Popocatépetl, México
• Sakura-jima, Kyushu (Japan)
• Santa María, Guatemala

Total: 21 volcanoes

Recent Volcano News

• Plosky Tolbachik Volcano Erupts March 5, 2013
• How Many Volcanoes Firing? March 7, 2013

Fuego Volcano Erupts

DISASTER CALENDAR SYMBOLIC COUNTDOWN: 1,280 Days Left

[September 13, 2012] Mass die-offs resulting from human impact and the planetary response to the anthropogenic assault could occur by early 2016. 

• SYMBOLIC COUNTDOWN: 1,280 Days Left to the ‘Worst Day’ in Human History

  Symbolic countdown to the ‘worst day’ in human history began on May 15, 2011...

  .

Global Disasters/ Significant Events

Guatemala’s Fuego volcano eruption forces tens of thousands of people to evacuate

Fuego’s powerful explosions ejected smoke and ash about 4km into the air, spewing two lava stream down the volcano flanks, accompanied by thousands of tons of volcanic ash and tephra.

About 35,000 people from two dozen villages nearest to the volcano have been evacuated, awaiting evacuation, or are on notice to abandon their homes depending on the wind direction, authorities said.

• The 3,763 m volcano, dubbed the ‘Volcano of Fire,’  sits about 10km SW of the colonial city of Antigua (Pop: ~ 50,000) , Guatemala’s former capital, and is one of Central America’s most active volcanoes.

 

Related Links

• San Cristóbal Eruption Forces Mass Evacuation Posted September 9, 2012

• Powerful Earthquake Strikes NW Costa Rica Posted September 6, 2012

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Global Disasters: Links, Forecasts and Background

• The First Wave of World’s Collapsing Cities
• Back to the Primordial Future
• The Fate of Energy Dinosaurs
• Mass Die-offs

• 2010 Disasters [Links to 2010 Disaster Calendar]
• Mega Disasters
• 2011 Disaster Calendar
• 2012 Disaster Calendar

GLOBAL WARNING

• WARNING: Human impact 2.85 x Earth’s diminishing carrying capacity
• WARNING: RAPID DECLINE IN PROGRESS!

Popocatépetl Volcano Erupts Explosively

‘El Popo’ forecast: Large-scale explosions, high probability of incendiary fragments and ash showers

Mexican authorities have raised the alert level for the Popocatepetl southeast of Mexico City following recent activity. The volcano’s eruption in 2000 forced the evacuation of tens of thousands of people from the three states that surround the volcano in central Mexico.

Popocatépetl Volcano (“smoking mountain” in Aztec) is North America’s 2nd-highest volcano. The massive stratovolcano stands 5,450m high and lies about 65 kilometers (40 miles)  southeast of  Mexico City (19.023°N, 98.622°W ) in the eastern segment of the Trans-Mexican volcanic belt. Mexico’s Center for Disaster Prevention (CENAPRED) has warned of large scale explosions, with high probability of  incendiary fragments and ash showers. Image source:  CENAPRED, Mexico.

A lava dome is growing in the volcano’s crater, CENAPRED said in a recent bulletin. The massive volcano also has been ejecting incandescent fragments and ash, and spewing steam and volcanic gasses.

The volcano is expected to experience “significant explosions with growing intensity, hurling incandescent rocks significant distances,” with a high probability of ash showers, the center said.  Adding that local residents should expect possible flows of lava and lahar down the volcano’s flanks.

The following is the latest bulletin issued by CENAPRED

Abr 18 07:00 (12:00 Abr 18 GMT)

At 06:35 h (local time), the monitoring system recorded the beginning of an exhalation sequence with tremor, that continues at the moment of this report. The first exhalation of this sequence had an explosive component. It generated the emission of incandescent fragments over the north and northeast flanks at distances of 500-800 m (see image 1) and a dense plume of steam, gases and ash (see image 2). The incandescent fragments fall over the snow and generated a small water and ash flow.

Likely, ash fall will occur over the villages in the eastern and southeastern sectors of the volcano.

During the 12 previous hours the monitoring system registered 6 low intensity exhalations, accompanied by steam, gas and small amount of ash. The most important occurred at 00:46 h y 04:59 h (see image 3), which increased the incandescence over the crater rim.

During the night the cloudy conditions doesn##t allow to observe the volcano. During the early morning the volcano could be seen with a continuous emission of steam and gas, that increased the amounts of ash and the density since 06:36 h.

The traffic light alert signal remains in Yellow Phase 3. This level implies:

1. Announcing the situation and measures taken to the public and the media. 2. Prepare personnel, equipment and evacuation shelters. 3. Implement specific measures in the most vulnerable. 4. Implement preventive measures against ash fall, lahars and against fragments in vulnerable regions. 5. Alert air navigation systems. 6. Limit access to the volcano over a larger area.

See also:

• Etna Erupts Explosively Posted on April 14, 2012

Related Links

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Global Disasters: Links, Forecasts and Background

• The First Wave of World’s Collapsing Cities
• Back to the Primordial Future
• Mass Die-offs

• 2010 Disasters [Links to 2010 Disaster Calendar]
• Mega Disasters
• 2011 Disaster Calendar
• 2012 Disaster Calendar: Collapse has already Begun

Etna Erupts Explosively

Mt Etna, Europe’s most active volcano, erupted for the sixth time this year

Etna’s spectacular eruption, which began Thursday, is the 24th explosion since January 2011.

Etna erupted explosively for the 6th time so far this year. Freeze frame from an AP news video clip.

Mount Etna (37.734°N, 15.004°E) is Europe’s highest volcano, towering 3,330m above Catania, Sicily’s second largest city. Photo by Jean-Claude Tanguy, 1991 (University of Paris). Source: GVP.

• News video clips show large volumes of lava and plumes of smoke and ash being ejected from a new crater on the volcano’s southeast flank.
• The massive volcano is located about 15km from the village of Zafferana Etnea and 30km from Catania, Sicily’s second largest city.
• Etna boasts  one of the world’s longest documented records of activity, with its historical volcanism dating back to 1500 BC.
• The latest eruption which began on Thursday is the 24th in a series that started in January 2011. The last three eruption have occurred in 12-day intervals.
• Also known as the “the Mountain of Fire,” the basaltic stratovolcano covers an area of about 1,200km².
• The Mongibello is in near constant state of activity.
• More than a quarter of Sicily’s population lives on the slopes of Mount Etna.

Related Links

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Global Disasters: Links, Forecasts and Background

• The First Wave of World’s Collapsing Cities
• Back to the Primordial Future
• Mass Die-offs

• 2010 Disasters [Links to 2010 Disaster Calendar]
• Mega Disasters
• 2011 Disaster Calendar
• 2012 Disaster Calendar: Collapse has already Begun

Cleveland and Kīlauea Remain at ORANGE Alert

Explosion destroys dome in Cleveland summit crater

Sudden explosions of blocks and ash may occur, while the volcano remains active, with the ash clouds rising to above 20,000 feet above sea level, AVO said.

• Elevation:  5,676 ft (1,730 m)
• Location: 52.8222° N, 169.945° W
• Quadrangle: Samalga

Mt Cleveland. Photo taken at 18:00 UTC on 11 Mar 2012 while transiting north through Samalga pass. Several small explosions were detected in days prior to the time of the photo, but very little ash is observed on the upper flanks.  Credit:  Matthew Davis/NOAA.

KILAUEA VOLCANO

19°25’16” N 155°17’13” W,
Summit Elevation 4091 ft (1,247 m)
Current Volcano Ale,rt Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary for past 24 hours:  The summit continued to inflate slowly while back-to-back DI events and sympathetic summit lava lake oscillations continued. Overnight, glow was visible within the Halema`uma`u gas plume and from sources within Pu`u `O`o crater. To the southeast, surface flows continued to be active on the pali and the coastal plain; there was no ocean entry. Seismic tremor levels were low; gas emissions were elevated: HVO

Kīlauea Volcano.  Active flows continued over a broad area on the coastal plain on April 5, 2012.  “This composite image combines a normal photograph and a thermal image to show the areas of active breakouts. Yellow areas are active flows while red areas are inactive, but still warm, flows. The flow front in the lower right was 1.6 km (1 mile) from the ocean,” HVO said.

Alert Level Increased for Iliamna Volcano, AK

Iliamna Activity – Color Code YELLOW Alert Level ADVISORY

Since January 2012 the earthquake rate at Iliamna Volcano has steadily increased and now exceeds normal background levels.

Iliamna Volcano. View from the SSE of Iliamna showing the prominent NE shoulder fumarole field near the summit. Note glacier disturbance (movement) on the east flank (upper Red Glacier).  Photo: Game McGimsey/AVO/USGS.

Pagan

Location: Mariana Islands  (18.13 ºN,  145.8 ºE)
Elevation: 570 m
Recent Eruption: 2006
Volcanic Alert Level: ADVISORY
Aviation Color Code: YELLOW

A gas and steam plume continued to extend downwind from the summit vent throughout the past week, but there were no further reports of unrest or activity at Pagan volcano, USGS said.

Other Volcanic Activity/ Unrest (Source: GVP)

New Activity/Unrest:

• Fuego, Guatemala
• Lewotobi, Flores Island (Indonesia)
• Nevado del Ruiz, Colombia
• Soufrière Hills, Montserrat
• Sundoro, Central Java (Indonesia)

Ongoing Activity:

• Etna, Sicily (Italy)
• Karymsky, Eastern Kamchatka (Russia)
• Popocatépetl, México
• Puyehue-Cordón Caulle, Central Chile
• Shiveluch, Central Kamchatka (Russia)
• Tengger Caldera, Eastern Java (Indonesia)
• Tungurahua, Ecuador

Related Links

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links

Volcanic Emissions: Hawaii County Declared Disaster Area

Hawaii County declared agricultural disaster area amid continuing volcanic emissions

The U.S. Department of Agriculture (USDA) has declared Hawaii County in Hawaii as a primary natural disaster area due to losses caused by volcanic emissions that began on January 1, 2011, and continue.

Disaster Calendar 2012 – February 11

[February 11, 2012]  Mass die-offs resulting from human impact and the planetary response to the anthropogenic assault could occur by early 2016.  SYMBOLIC COUNTDOWN: 1,495 Days Left to the ‘Worst Day’ in Human History

• Hawaii.  USDA has declared Hawaii County a primary natural disaster area due to agricultural losses caused by volcanic emissions that began on January 1, 2011, and continue.

HAWAIIAN VOLCANO OBSERVATORY DAILY UPDATE
Friday, February 10, 2012 7:14 AM HST (Friday, February 10, 2012 17:14 UTC)

KILAUEA VOLCANO
19°25’16” N 155°17’13” W, Summit Elevation 4,091 ft (1,247 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE

Activity Summary for past 24 hours: Overall eruptive activity was low. DI deflation and dropping of the summit lava lake started this morning. Within Pu`u `O`o Crater, glow was visible from sources on the northeast and southeast edges of the floor.  Surface flows southeast of Pu`u `O`o remained active but there were no active surface flows on the pali, coastal plain, or entering the ocean. Seismic tremor levels were low and gas emissions were elevated. (Source: HVO)

This photograph shows the east rim of Pu`u `Ō `ō crater. A collapsed spatter cone revealed a swiftly flowing stream of lava heading northeast, into the tube system that supplies the active flow field. The active flows today were 6 km (3.7 miles) southeast of Pu`u `Ō `ō. Dated 8 February 2012.  (Source: HVO)

Map showing the extent of lava flows erupted during Kīlauea’s ongoing east rift zone eruption and labeled with the years in which they were active. Episodes 1–48b (1983–1986) are shown in dark gray; Episodes 48c–49 (1986–1992) are pale yellow; Episodes 50–53 and 55 (1992–2007) are tan; Episode 54 (1997) is yellow; Episode 58 (2007–2011) is pale orange; the episode 59 Kamoamoa eruption (March 2011) is at left in light reddish orange; and the episode 60 Pu‘u ‘Ō‘ō overflows and flank breakout (Mar–August 2011) is orange. The currently active flow (episode 61) is shown as the two shades of red—pink is the extent of the flow from September 21, 2011, to January 26, 2012, and bright red marks flow expansion from January 26 to February 8. The active lava tube is delineated by the yellow line within the active flow field. The contour interval on Pu‘u ‘Ō‘ō is 5 m.  (Source: HVO)

Global Disasters: Links, Forecasts and Background

• The First Wave of World’s Collapsing Cities
• Back to the Primordial Future
• Mass Die-offs

• 2010 Disasters [Links to 2010 Disaster Calendar]
• Mega Disasters
• 2011 Disaster Calendar

Heightened Activity at Kilauea Volcano

New Fissure at  Kilauea Spews Lava 25m into the Air

HAWAIIAN VOLCANO OBSERVATORY CURRENT STATUS REPORT
Sunday, March 6, 2011 6:34 PM HST (Monday, March 7, 2011 04:34 UTC)

KILAUEA VOLCANO (CAVW#1302-01-)
19.42°N 155.29°W, Summit Elevation 4,091 ft (1,247 m)
Volcano Alert Level: WARNING
Aviation Color Code: RED

HVO said: “A fissure that opened on Kilauea’s east rift zone after yesterday’s collapse of the Pu’u ‘O’o crater floor continues to erupt lava. Activity along the fissure was sporadic overnight and throughout today, with periods of quiet punctuated by episodes of lava spattering up to 25 m (80 ft) high.”

Fire Earth: A new fissure at Kilauea Volcano on the Big Island of Hawaii spatters lava

A close-up of spattering fissure. Credit: HVO. Click image to enlarge.

View looking at the NE end of the actively propagating fissure. Lava is just breaking the surface in foreground crack.  Credit: HVO. Click image to enlarge.

• To view a video of this event click here.

Ash cloud rising from Pu`u `Ō `ō as crater floor collapses [5 March 2011]

Ash cloud rising from Pu`u `Ō `ō as crater floor collapses due to magma withdrawal. Incandescent rubble can be seen crumbling and rolling down the scarp. The east rim of Pu`u `Ō `ō is in the foreground. Credit: HVO

Several video clips showing wall and rim collapses of Halema`uma`u

There was a series of vent wall and rim collapses on March 3, much like those than occurred in January and February. This video, compiled from the Webcam on the rim of Halema`uma`u above the vent, is one of the larger collapses, and shows the northwest rim of the vent falling into the lava lake. Credit: HVO. Click image to view the video clip.

• Video clip 2 HCAM March 3, 2011

Click image to view a clip captured by a video camera on the rim of Halema`uma`u to the southwest of the vent, showing a small chunk of the western rim of the vent collapsing into the lava lake.  Credit: HVO.

Archive image of lava from a previous eruption at Kilauea Volcano.  Credit: HVO

Source: [http://www.lib.utexas.edu/maps/united_states Perry-Castañeda Library Map Collection]

Map showing the extent of the “July 2007 eruption”, or Episode 58, flow field relative to surrounding communities. Reddish-brown is the active flow as mapped on January 13, 2011, while bright red shows the advancement of the flow from January 13-February 4. Light red represents older flows erupted during Episode 58 of the ongoing East Rift Zone eruption. Episode 58 started in July 2007. Flows erupted during 1983-2007 are shown in more muted colors and labeled with the years in which they were active. Click image to enlarge. Credit: HVO

Map showing the extent of the active flows. Reddish-brown is the flow as mapped on February 4, 2011, while bright red shows the advancement of the flow from January 13-February 4. Small ocean entries remains active at the front of both the western and eastern branches of the flow. Light red represents older flows erupted during Episode 58 of the ongoing East Rift Zone eruption. Episode 58 started in July 2007. Lava erupted while Kupaianaha was active from 1986-1992 (Episode 48) is shown in light yellow. Click image to enlarge. Credit: HVO

The Big Island, Hawaii

The Island of Hawaiʻi (the Big Island or Hawaiʻi Island) is a volcanic island With an area of 4,028 square miles (10,432 km²), it is the largest island in the United States and larger than all of the other Hawaiian Islands combined.

The Island of Hawaiʻi is built from five separate shield volcanoes that erupted somewhat sequentially, one overlapping the other. These are (from oldest to youngest):

• Kohala (dormant),
• Mauna Kea (dormant),
• Hualālai (dormant),
• Mauna Loa (active, partly within Hawaiʻi Volcanoes National Park), and
• Kīlauea (very active; part of Hawaiʻi Volcanoes National Park).

This simulated true-color image of the island of Hawai’i was derived from data gathered by the Enhanced Thematic Mapper plus (ETM+) on the Landsat 7 satellite between 1999 and 2001. Image: NASA/NOAA

The lava fountain on shield 3 (12-15 m high). USGS Archive image.

Related Links:

• Kilauea Volcano Continues to Discharge Lava
• Kilauea — Perhaps the World’s Most Active Volcano [Introduction]

• Huge amounts of lava continue to flow from world’s most active volcano in Hawaii, damaging an unoccupied home (Video)
• New Kilauea volcano land collapses explosively into ocean

• Emissions from Kilauea Volcano Brochure
• Lava Viewing Safety Card
• Department of Health Notification of Elevated SO2 and Particulate Levels

• Hawai‘i Volcanoes National Park
• More images
• Maps

• Halema`uma`u webcam
• Pu`u `Ō `ō webcam

Other Volcano News:

New Zealand’s Mount Ruapehu crater lake has heated up to 40ºC, reported to be the lake’s third-highest temperature rise in 10 years.

HVO Links:

Kīlauea Update | Mauna Loa Status | Deformation | Maps | Webcams | Images | Movies

Kīlauea Summit
Halema`uma`u from HVO	Halema`uma`u from Overlook
Kīlauea East Rift Zone
Pu`u `Ō `ō	Thanksgiving Eve Breakout From Pu`u `Ō `ō
Napau Crater
Mauna Loa Summit
Mokuawe`owe`o, Mauna Loa Summit Caldera

Nyiragongo Unrest

Plume from Nyiragongo

Nyiragongo Volcano in the Democratic Republic of the Congo released a small plume on June 27, 2009, as the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite passed overhead.

NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensors detected hotspots on six different occasions between April 10 and May 4, 2009.  The plume observed by ALI in late June may be a continuation of the low-level activity.

Nyiragongo is a stratovolcano—a steep-sloped structure made of alternating layers of solidified ash, hardened lava, and rocks released by previous eruptions. In contrast to the low profile of neighboring Nyamuragira, Nyiragongo rises to a height of 3,470 meters (11,384 feet) above sea level. Lava flows from Nyiragongo caused substantial casualties in 1977 and 2002.  NASA image created by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 Team. Caption by Michon Scott. [Edited by FEWW.]

Related Links:

• Earthquakes
• Volcanoes
• FEWW Volcano Links

Sarychev Peak Before and After Images

Before and after images show impact of  the Sarychev Peak Volcano eruption on Matua Island.

Ostrov Matua, Kuril Islands

Image dated June 30, 2009

Image dated May 26, 2007

Acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite, these images of Ostrov Matua show the island shortly after the eruption on June 30, 2009 (top), and two years before on May 26, 2007 (bottom).

In these false-color images, vegetation appears red, water appears dark blue, and clouds, water vapor and ice all appear white. Volcanic rock, including old lava flows and debris from the recent eruption, ranges from gray to dark brown.

The most striking difference between these two images is the gray coating on the northwestern half of the island in June 2009. While vegetation on the rest of the island appears lush, volcanic debris—probably a mixture of pyroclastic flows and settled ash—covered virtually all the vegetation on the northwestern end. A close look at the top image also reveals that the recent volcanic activity appears to have expanded the island’s coastline on the northwestern end.

Another difference between the images relates to snow cover. In the image from May 2007, snow spreads over much of the island, although the snow alternates with snow-free ground. The vegetation is pinkish-gray, suggesting the spring thaw is still underway. The complete lack of snow in 2009 may result from a combination of a difference in season and volcanic activity having melted or covered any lingering snow.

NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Michon Scott.

Related Links:

• Shiveluch spewes large plumes of ash
• How Sarychev Peak Moved from Russia to Japan!
• VolcanoWatch Weekly [25 June 2009]
• VolcanoWatch Weekly [18 June 2009]
• Sarychev Peak Spews Two Plumes of Ash

Two Volcanoes Erupt in Japan

Japan’s Asama volcano and Mount Sakurajima erupted early Monday, Asama spewing hot rocks and raining ash as far away as Tokyo.

Residents in population centers near Mount Asama about 150 kilometers (95 miles) northwest of Tokyo were advised to wear masks as Asama ejected fumes, hot rocks and ash about 1:51 am local time, spewing lava shortly afterward.

White smoke rises from Mount Asama in Tsumagoi, about 140 km (87 miles) northwest of Tokyo, Feb. 2, 2009. The volcano in central Japan erupted on Monday, spewing hot rocks and ash, but there was no major damage in the sparsely populated vicinity, the Japan Meteorological Agency said.  (Xinhua/Reuters Photo). Image may be subject to copyright.

The 2,568-meter (8,425-foot) volcano ejected a plume of fumes and ash about 2km into the air, covering the towns at the foot of Mt Asama with white volcanic ash.  The volcanic ash also reached Tokyo, traveling as far as Yokohama city southeast of Japan’s capital.

Mount Asama has been active for several thousand years, and frequently ejects small amounts of ash from its crater. It last erupted in August 2008, however, its last major eruption occurred on September 1, 2004, spewing hot rock and sprinkling ash as far as 180 km away, and causing damage to crops.  In 1783 it erupted violently causing extensive damage to property and killing as many as 2,000 people.

Japan’s meteorological agency also reported that Mount Sakurajima, a 1,117-metre (3,686-foot) volcano, had erupted eight times between Sunday evening and early Monday Morning.

Home to some 108 active volcanoes, Japan sits atop the Eurasian, Pacific, Philippine and North American tectonic plates whose movements cause numerous earthquakes and volcanic eruptions. The country experiences about 20 percent of the world’s major earthquakes of magnitude 6 or greater.

Asama, Honshu’s most active volcano, overlooks the resort town of Karuizawa, 140 km NW of Tokyo. The volcano is located at the junction of the Izu-Marianas and NE Japan volcanic arcs. The modern cone of Maekake-yama forms the summit of the volcano and is situated east of the horseshoe-shaped remnant of an older andesitic volcano, Kurofu-yama, which was destroyed by a late-Pleistocene landslide about 20,000 years before present (BP). Growth of a dacitic shield volcano was accompanied by pumiceous pyroclastic flows, the largest of which occurred about 14,000-11,000 years BP, and by growth of the Ko-Asama-yama lava dome on the east flank. Maekake-yama, capped by the Kama-yama pyroclastic cone that forms the present summit of the volcano, is probably only a few thousand years old and has an historical record dating back at least to the 11th century AD. Maekake-yama has had several major plinian eruptions, the last two of which occurred in 1108 (Asama’s largest Holocene eruption) and 1783 AD. Caption: Global Volcanism program. Photo by Richard Fiske, 1961 (Smithsonian Institution).

Sakura-jima, one of Japan’s most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km wide Aira caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakura-jima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu’s largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76. Caption: GVP

Copyrighted photo by Shun Nakano (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/).

Related Links:

• Volcanoes [Links page]
• Earthquake Forecast 2009 : Japan
• A New Era of Intense Volcanic Unrest May Have Begun