383010 - 285010
(was 0802-0805)
Japan Meteorological Agency (JMA)
Volcanological Division
Seismological and Volcanological Department
1-3-4 Ote-machi, Chiyoda-ku
Tokyo 100-8122
Japan

Tokyo Volcanic Ash Advisory Centre
1-3-4 Ote-machi, Chiyoda-ku
Tokyo 100-8122
Japan

Volcanological Research Department
Meteorological Research Institute
1-1 Nagamine, Tsukuba-shi, Ibaraki-ken 305-0052
Japan

Kakioka Magnetic Observatory
Kakioka 595, Yasato-machi, Niihari-gun, Ibaraki-ken 315-0116
Japan

VOLCANOLOGICAL DIVISION

           52 staff members

There are 110 active volcanoes in Japan. Eruption or abnormal phenomena are observed approximately at 10 volcanoes a year on average, sometimes causing great disasters. The Japan Meteorological Agency (JMA) has defined active volcanoes in Japan as "volcanoes which have erupted within 10,000 years or volcanoes with vigorous fumarolic activity".

JMA monitors 47 active volcanoes on a 24/7 basis with seismometers and other equipments, and dispatches mobile observation teams to less active volcanoes when needed.

When volcanoes become unrest, JMA issues volcano information.

JMA has been making a concerted effort to predict volcanic eruption in accordance with the Volcanic Eruption Prediction Program through accumulating data, building up expertise and promoting relevant research. As volcanic phenomena are very complicated, Meteorological Research Institute and Kakioka Magnetic Observatory mentioned below are engaged in research and development activities related to volcanic eruption process.

Organization of JMA:

JMA consists of headquarters, field offices, and auxiliary organs. The headquarters is located in the heart of Tokyo, made up of five Departments which are responsible for administering and planning of respective tasks: forecasts; observations; earthquakes and volcanoes; climate and marine affairs; and administration which deals overall planning, aeronautical meteorology, private secter development, finance and personnel. Some of the Divisions under these Departments also function as a national or a regional operational center for specific tasks --- conducting numerical weather predictions, issuing forecasts or directing local forecast services, issuing maritime forecast, and monitoring earthquakes and forecasting tsunamis.

There are six District Meteorological Observatories including Okinawa in the respective areas. These Observatories lead Local Meteorological Observatories and Weather Stations; they also operate as regional centers for directing regional weather forecast, monitoring regional earthquakes and volcanoes. There is at least one Meteorological Observatory in a prefecture. These Observatories work as a contact point for local authorities and regional disaster-prevention organizations representing JMA.

In addition, there are four Marine Observatories. These Observatories work not only for marine and maritime meteorological observation but also for regional weather services in each area.

OBSERVATION REGIME OF JMA

The JMA constantly conducts seismic and infrasonic observations, ground deformation observation, visual observation and other observations at 47 active volcanoes. Volcano Observations and Information Centers (VOIC) were established in the Headquarters in Tokyo and Sapporo, Sendai and Fukuoka District Meteorological Observatories in 2001. The data obtained at each site are transmitted to the relevant VOICs. Based on the observation results, VOICs release volcano information which is conveyed to the general public through various channels.

SEISMIC OBSERVATION

Seismic observation is conducted to observe volcanic earthquakes and tremors. JMA is analyzing sources and wave forms of them to investigate state of volcanoes.

GROUND DEFORMATION OBSERVATION

In a volcano area, change of ground tilt, and expansion and contraction are produced in accordance with magmatic activity. Ground deformation observations are conducted with the tiltmeter and GPS which are installed around volcano.

VISUAL OBSERVATION

A visual observation is conducted to observe height and color of plume, erupted materials (ash fall, volcanic bombs, etc.) and other volcanic phenomena from a fixed point. Some of the volcanoes are continuously monitored using volcano visual observation equipment (high-sensitivity cameras that can observe volcanoes at night, or visible and infrared cameras).

INFRASONIC OBSERVATION

Infrasonic waves are excited by an atmospheric pressure change by eruption or explosion, and are utilized to detect an eruption and evaluate its magnitude. Infrasonic waves are observed with low frequency microphones that were installed at volcanoes.

MOBILE OBSERVATIONS OF VOLCANOES

VOICs dispatch mobile observation teams in order to monitor state of volcanic activity. Mobile observation is carried out periodically or emergently.

With infrared thermal image equipment, the high temperature region of the fumarole circumference is caught in situ. The change of volcanic activity is monitored by observing the state of the far-reaching thermal activity.
By observing change of the composition ratio or the amount of discharge of various volcanic gas, the underground state and underground volcanic activity of magma are investigated.
In the comparatively narrow domain around activity region, GPS observation equipment is installed in the fixed point, and the state of volcanic activity is monitored by observing ground deformation in a local area.
Activity of the magma inside a volcano changes the value of the geomagnetism near the volcano. To observe the change of such geomagnetism, the thermal state inside a volcano is monitored.
In a place where approach is difficult because of volcanic activity or other reason, various observation for monitoring volcanic activity is performed using an unmanned remote control helicopter and Kite with engine as a means to observe without infringing on danger.

THE LIST OF OBSERVATORIES OF JMA:
Observatory (number of staff), Watching Volcano, Continuous observation method:
Seis = Seismic Observation                TV = Visual Observation with TV camera
GPS = GPS Observation                     Infr = Infrasonic Observation
Tilt = Tiltmeter Observation               EDM = EDM Observation
Mag = Geomagmetic Observation       Gas = Gas density Observation)______________

Sapporo VOIC (16)

Atosanupuri     Seis TV GPS Infr Tilt
Meakandake    Seis TV GPS Infr Tilt Mag
Taisetsuzan     Seis TV Infr 
Tokachidake    Seis TV GPS Infr Tilt
Tarumaesan    Seis TV GPS Infr Tilt
Kuttara           Seis TV GPS Infr Tilt
Usuzan           Seis TV GPS Infr Tilt
Hokkaido-Komagatake Seis TV GPS Infr Tilt
Esan              Seis TV GPS Infr Tilt

Sendai VOIC (16) 

Iwakisan        Seis TV GPS Infr Tilt
Akita-Yakeyama  Seis TV GPS Infr Tilt
Iwatesan        Seis TV GPS Infr Tilt 
Akita-Komagatake Seis TV GPS Infr Tilt
Chokaisan      Seis TV GPS Infr Tilt
Kurikomayama    Seis TV Infr Tilt
Zaozan          Seis TV GPS Infr Tilt 
Azumayama   Seis TV GPS Infr Tilt Gas
Adatarayama  Seis TV GPS Infr Tilt
Bandaisan      Seis TV GPS Infr Tilt

Headquarters (52)
 (including Tokyo VOIC)

Nasudake      Seis TV GPS Infr Tilt
Nikko-Shiranesan    Seis TV GPS Infr Tilt
Kusatsu-Shiranesan Seis TV GPS Infr Tilt Mag
Asamayama  Seis TV GPS Infr Tilt EDM Gas
Niigata-Yakeyama    Seis GPS Infr Tilt
Yakedake      Seis TV GPS Infr Tilt
Norikuradake Seis TV GPS Infr Tilt
Ontakesan    Seis TV GPS Infr Tilt
Hakusan       Seis TV Infr
Fujisan         Seis TV GPS Infr Tilt
Hakoneyama Seis TV GPS Infr Tilt
Izu-Tobu Volcanoes Seis TV GPS Infr Tilt
Izu-Oshima   Seis TV GPS Infr Tilt EDM Mag
Niijima          Seis TV GPS Infr Tilt
Kozushima    Seis TV GPS Infr Tilt
Miyakejima   Seis TV GPS Infr Tilt Mag Gas
Hachijojima   Seis TV GPS Infr Tilt
Aogashima    Seis TV GPS Infr Tilt
Ioto              Seis TV Infr

Fukuoka VOIC (18)
* Kirishimayama and Sakurajima are also observed by Kagoshima Local Meteorological Observatory (6).

Tsurumidake and Garandake   Seis TV GPS Infr
Kujusan        Seis TV GPS Infr Tilt
Asosan         Seis TV GPS Infr Tilt Mag Gas 
Unzendake    Seis TV GPS Infr Tilt
Kirishimayama* Seis TV GPS Infr Tilt Gas
Sakurajima* Seis TV GPS Infr Tilt Gas
Satsuma-Iojima Seis TV GPS Infr
Kuchinoerabujima Seis TV GPS Infr Tilt
Suwanosejima Seis TV GPS Infr Tilt