Logo link to homepage

Smithsonian / USGS Weekly Volcanic Activity Report

You are currently viewing Archived reports for the week of 29 June-5 July 2005.


















 Activity for the week of 29 June-5 July 2005

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.

Name Location Activity
Cleveland Chuginadak Island (USA) New
Fukutoku-Oka-no-Ba Volcano Islands (Japan) New
Nyamuragira DR Congo New
Soufriere Hills Montserrat New

Anatahan Mariana Islands (USA) Ongoing
Bagana Bougainville (Papua New Guinea) Ongoing
Colima Mexico Ongoing
Karymsky Eastern Kamchatka (Russia) Ongoing
Kilauea Hawaiian Islands (USA) Ongoing
Manam Papua New Guinea Ongoing
Reventador Ecuador Ongoing
Sheveluch Central Kamchatka (Russia) Ongoing
St. Helens United States Ongoing
Tungurahua Ecuador Ongoing
Ulawun New Britain (Papua New Guinea) Ongoing


New Activity / Unrest


Volcano index photo  Cleveland  | Chuginadak Island (USA)  | 52.825°N, 169.944°W  | Elevation 1730 m

Satellite imagery of Cleveland taken during 24 June to 1 July showed increased heat flow from the volcano and a possible debris flow. AVO stated that although observations were inhibited by cloudy weather, they indicated the possibility of increased volcanic activity. AVO did not assign a Concern Color Code to Cleveland due to the lack of seismic monitoring at the volcano and limited satellite observations. The last eruption at Cleveland began in February 2001 when three explosive events produced ash clouds as high as 12 km (39,400 ft) a.s.l.

Source: US Geological Survey Alaska Volcano Observatory (AVO)



Volcano index photo  Fukutoku-Oka-no-Ba  | Volcano Islands (Japan)  | 24.285°N, 141.481°E  | Elevation -29 m

On the evening of 2 July, members of the Japan Coast Guard observed a steam plume rising ~1 km above the sea near the island of Minami-Iwo-jima. On 3 July, JMA confirmed that a small-scale eruption had occurred at the submarine volcano Fukutoku-Okanoba, prompting the Japan Coast Guard to issue a warning against sailing in the area. Observers saw rock and mud rising to the sea's surface near the volcano and a ~1-square-km area of water that had turned orange-brown. As of 4 July, a new island had not formed.

Sources: Daily Yomiuri News, Reuters, Associated Press



Volcano index photo  Nyamuragira  | DR Congo  | 1.408°S, 29.2°E  | Elevation 3058 m

GVO reported that a significant seismic crisis occurred at Nyamuragira during several days in late June. The crisis consisted of swarms of mainly long-period earthquakes, which increased in number daily and peaked on 26 and 27 June. The swarms were recorded by the entire seismic network at the volcano, as far away as 90 km S of the volcano. Most of the events occurred within a 10 km radius around Nyamuragira's summit caldera and were aligned roughly N-S. The depths of the earthquakes ranged from 0 to 30 km, with two main areas of concentration; one between 15 and 25 km deep, and the other between 0 and 4 km. Based on precursory activity before previous historical eruptions at Nyamuragira, GVO reported that a new eruption might occur in the next 2-4 months. They stressed that an eruption from Nyamuragira would not threaten the city of Goma or other inhabited areas.

Sources: Observatoire Volcanologique de Goma (OVG), Jacques Durieux, UN Program Manager



Volcano index photo  Soufriere Hills  | Montserrat  | 16.72°N, 62.18°W  | Elevation 915 m

During 24 June to 1 July, seismic and volcanic activity at Soufrière Hills was elevated in comparison to the previous week. Periodic episodes of intense ash venting continued during the report period, culminating in an explosive event beginning on 28 June at 1306. During the event, ballistics were ejected onto the Farrell's plain (to the NW) and a column collapse produced pyroclastic flows. The pyroclastic flows reached the sea at the Tar River delta (to the NE) and a smaller volume of material flowed into the top of Tyre's Ghaut (to the N). Ash analyses from a venting episode on 13 June did not indicate the presence of fresh magma.

Preliminary analysis of recent ground deformation data from the GPS network at the volcano showed that deflation during April to mid June 2005 had later reversed, and the volcano appeared to be inflating. The daily recorded sulfur-dioxide flux varied from 300 metric tons per day (t/d) on 28 June to 700 t/d on 29 June, with an average of 470 t/d for the week.

Source: Montserrat Volcano Observatory (MVO)



Ongoing Activity


Volcano index photo  Anatahan  | Mariana Islands (USA)  | 16.35°N, 145.67°E  | Elevation 790 m

On 3 July at 1646 an eruption at Anatahan produced a SSE-drifting plume to a height of ~12.2 km (~40,000 ft) a.s.l. according to Guam Meteorological Office radar. Volcanic fog (vog) briefly drifted S over the islands of Saipan and Tinian. During the rest of 29 June to 5 July, steam-and-ash emissions continued to rise to low levels.

Source: Emergency Management Office of the Commonwealth of the Mariana Islands and United States Geological Survey Volcano Hazards Program



Volcano index photo  Bagana  | Bougainville (Papua New Guinea)  | 6.137°S, 155.196°E  | Elevation 1855 m

A thin plume emitted from Bagana was visible on satellite imagery on 30 June. The height of the plume was not reported.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)



Volcano index photo  Colima  | Mexico  | 19.514°N, 103.62°W  | Elevation 3850 m

Ash emission continued at Colima during 29 June to 5 July. On 30 June, lahars traveled SW down La Lumbre Ravine and SSE down Montegrande Ravine to a maximum length of ~10 km. The lahars did not reach populated areas. Due to heavy rain, and ash on the flanks of the volcano, Universidad de Colima advised avoiding the ravines of La Lumbre, San Antonio, Monte Grande (in Colima state), and La Arena (in Jalisco state). The Washington VAAC reported that the Colima video camera and satellite imagery confirmed that an explosive eruption occurred at Colima on 5 July at 1821. The Mexico City MWO reported that the resultant ash plume reached a height of ~9.1 km (~29,900 ft) a.s.l. and drifted NW. According to the Colima Volcano Observatory, pyroclastic flows accompanying the eruption traveled down Colima's E flank.

Sources: Centro Universitario de Estudios e Investigaciones de Vulcanologia - Universidad de Colima, Washington Volcanic Ash Advisory Center (VAAC)



Volcano index photo  Karymsky  | Eastern Kamchatka (Russia)  | 54.049°N, 159.443°E  | Elevation 1513 m

Satellite imagery of Karymsky showed a narrow ash-and-gas plume at a height of ~3.5 km (11,500 ft) a.s.l. on 30 June. Based on interpretations of seismic data, ash-and-gas plumes may have reached heights of 3 km above the volcano's crater (14,900 ft a.s.l.). Karymsky was at Concern Color Code Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)



Volcano index photo  Kilauea  | Hawaiian Islands (USA)  | 19.421°N, 155.287°W  | Elevation 1222 m

Lava from Kilauea entered the sea during 4-5 July, and few surface lava flows were visible on the Pulama pali fault scarp. Background volcanic tremor remained above normal levels at Kilauea's summit and at moderate levels at Pu`u `O`o. Slight inflation and deflation occurred at the volcano. According to a news report, around 3 July a lava-viewing area was closed at Kilauea due to the increased chance of a 10-hectare size lava bench (land built out from the sea cliff) in the vicinity collapsing without warning.

Sources: US Geological Survey Hawaiian Volcano Observatory (HVO), Associated Press



Volcano index photo  Manam  | Papua New Guinea  | 4.08°S, 145.037°E  | Elevation 1807 m

Thin plumes from Manam were visible on satellite imagery during 1-2 July. The plume heights were not reported.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)



Volcano index photo  Reventador  | Ecuador  | 0.077°S, 77.656°W  | Elevation 3562 m

During 30 June to 5 July, gas-and-ash emissions continued at Reventador. Plumes rose to a maximum height of 7 km (23,000 ft) a.s.l.

Sources: Instituto Geofísico-Escuela Politécnica Nacional (IG), Washington Volcanic Ash Advisory Center (VAAC)



Volcano index photo  Sheveluch  | Central Kamchatka (Russia)  | 56.653°N, 161.36°E  | Elevation 3283 m

During 24 June to 1 July, satellite imagery of Shiveluch showed a persistent thermal anomaly and fumarolic activity producing steam to 4-5 km (13,100-16,400 ft) a.s.l. On 30 June, ash-and-gas plumes rose 3-5 km (9,800-16,400 ft) a.s.l. and drifted NW. Hot avalanches of volcanic material were also recorded during the report week. Shiveluch remained at Concern Color Code Orange.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)



Volcano index photo  St. Helens  | United States  | 46.2°N, 122.18°W  | Elevation 2549 m

During 29 June to 5 July, growth of the new lava dome inside the crater of Mount St. Helens continued, accompanied by seismic and deformation data trends similar to those of the previous few weeks. On 2 July at 0630 a rockfall from the growing lava dome removed a large piece of the top of the dome, producing an ash plume that rose above the crater rim and generating a substantial seismic signal. Persistent smaller rockfalls from the growing lava dome built talus aprons on the W and NE flanks of the dome.

Source: US Geological Survey Cascades Volcano Observatory (CVO)



Volcano index photo  Tungurahua  | Ecuador  | 1.467°S, 78.442°W  | Elevation 5023 m

During 1-5 July, volcanic and seismic activity were at relatively low levels at Tungurahua. Low-energy plumes were emitted that were composed of gas, steam, and occasionally small amounts of ash. The plumes rose to a maximum height of ~5.8 km (19,000 ft) a.s.l. on 4 July.

Source: Instituto Geofísico-Escuela Politécnica Nacional (IG)



Volcano index photo  Ulawun  | New Britain (Papua New Guinea)  | 5.05°S, 151.33°E  | Elevation 2334 m

During 30 June to 1 July, thin ash plumes from Ulawun were visible on satellite imagery. The plume heights were not reported.

Source: Darwin Volcanic Ash Advisory Centre (VAAC)



Weekly Reports Archive

Search by Volcano
Agung Fuego Little Sitkin San Cristobal
Ahyi Fujisan Llaima San Miguel
Aira Fukutoku-Oka-no-Ba Loihi San Vicente
Akan Galeras Lokon-Empung Sangay
Alaid Galunggung Lopevi Sangeang Api
Alu-Dalafilla Gamalama Machin Santa Ana
Ambae Gamkonora Makian Santa Maria
Ambang Gaua Makushin Sarigan
Ambrym Gorely Maly Semyachik Sarychev Peak
Anatahan Great Sitkin Manam Saunders
Antuco Grimsvotn Manda Hararo Semeru
Apoyeque Guagua Pichincha Marapi Semisopochnoi
Arenal Guallatiri Maroa Seulawah Agam
Asamayama Guntur Martin Sheveluch
Askja Hachijojima Masaya Shishaldin
Asosan Hakoneyama Mauna Loa Simbo
Augustine Heard Mayon Sinabung
Avachinsky Hekla McDonald Islands Sinarka
Awu Hierro Melimoyu Siple
Axial Seamount Hokkaido-Komagatake Merapi Sirung
Azul, Cerro Home Reef Midagahara Slamet
Azumayama Hood Misti, El Soputan
Bagana Hudson, Cerro Miyakejima Sorikmarapi
Balbi Huila, Nevado del Momotombo Sotara
Bamus Hunga Tonga-Hunga Ha'apai Monowai Soufriere Hills
Banda Api Ibu Montagu Island Soufriere St. Vincent
Bardarbunga Ijen Moyorodake [Medvezhia] South Sarigan Seamount
Barren Island Iliamna Mutnovsky Spurr
Batur Iliwerung Myojinsho St. Helens
Bezymianny Inielika Nabro Stromboli
Bogoslof Ioto Negra, Sierra Sulu Range
Brava Iya Negro, Cerro Sumbing
Bristol Island Izu-Torishima Nightingale Island Sundoro
Bulusan Jackson Segment Nishinoshima Suretamatai
Calbuco Kaba Nisyros Suwanosejima
Callaqui Kadovar Novarupta Taal
Cameroon Kambalny NW Rota-1 Tair, Jebel at
Campi Flegrei del Mar di Sicilia Kanaga Nyamuragira Takawangha
Cayambe Kanlaon Nyiragongo Talang
Cereme Karangetang Okataina Tambora
Chachadake [Tiatia] Karkar Okmok Tanaga
Chaiten Karthala Ontakesan Tandikat-Singgalang
Chiginagak Karymsky Oraefajokull Tangkoko-Duasudara
Chikurachki Kasatochi Osorno Tangkuban Parahu
Chiles-Cerro Negro Katla Pacaya Tara, Batu
Chillan, Nevados de Kavachi Pagan Telica
Chirinkotan Kelimutu Palena Volcanic Group Tenerife
Chirpoi Kelut Paluweh Tengger Caldera
Cleveland Kerinci Panarea Three Sisters
Colima Ketoi Papandayan Tinakula
Colo Kharimkotan Parker Tofua
Concepcion Kick 'em Jenny Pavlof Tokachidake
Copahue Kikai Peuet Sague Tolbachik
Cotopaxi Kilauea Pinatubo Toliman
Cuicocha Kirishimayama Planchon-Peteroa Tongariro
Cumbal Kizimen Poas Tungurahua
Dabbahu Klyuchevskoy Popocatepetl Turrialba
Dempo Kolokol Group Puyehue-Cordon Caulle Ubinas
Descabezado Grande Korovin Rabaul Ulawun
Dieng Volcanic Complex Koryaksky Raikoke Unknown Source
Dukono Krakatau Ranakah Unnamed
Ebeko Krummel-Garbuna-Welcker Raoul Island Unnamed
Ebulobo Kuchinoerabujima Rasshua Veniaminof
Egon Kurikomayama Raung Villarrica
Ekarma Kusatsu-Shiranesan Redoubt West Mata
Epi Kverkfjoll Reventador White Island
Erebus Lamington Rincon de la Vieja Witori
Erta Ale Lamongan Rinjani Wolf
Etna Langila Ritter Island Yasur
Etorofu-Yakeyama [Grozny Group] Lanin Rotorua Zaozan
Eyjafjallajokull Lascar Ruang Zavodovski
Fernandina Lateiki Ruapehu Zhupanovsky
Fogo Lengai, Ol Doinyo Ruiz, Nevado del Zubair Group
Fonualei Leroboleng Sabancaya
Fournaise, Piton de la Lewotobi Sakar
Fourpeaked Lewotolo Salak
Search by Date
Use the dropdowns to choose the year and week for archived Weekly Reports.





 News Feeds and Google Placemarks


The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website.




The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.




A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.

 Criteria & Disclaimers

Criteria

The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:

- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.

Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.

It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.


Disclaimers

1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.

3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

5. USGS Disclaimer Statement for this Website:

Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

Some of the documents on this server may contain live references (or pointers) to information created and maintained by other organizations. Please note that USGS does not control and cannot guarantee the relevance, timeliness, or accuracy of these outside materials.

For site security purposes and to ensure that this service remains available to all users, this government computer system employs software programs to monitor network traffic to identify unauthorized attempts to upload or change information, or otherwise cause damage. Unauthorized attempts to upload information or change information on this website are strictly prohibited and may be punishable under the Computer Fraud and Abuse Act of 1986 and the National Information Infrastructure Protection Act. Information may also be used for authorized law enforcement investigations. (Last modified September 21, 1999.)

U.S. Department of the Interior, U.S. Geological Survey, Reston, VA, USA
URL https://volcano.si.edu/reports_weekly.cfm
Contact: USGS Web Team
USGS Privacy Statement


RSS and CAP Feeds

An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.

At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.

CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management.


Google Earth Placemarks

A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.

 Acronyms and Abbreviations

a.s.l. - above sea level

AVO - Alaska Volcano Observatory

AVHRR - Advanced Very High Resolution Radiometer

CENAPRED - Centro Nacionale de Prevencion de Desastres (México)

CONRED - Coordinadora Nacional para la Reducción de Desastres

COSPEC - Correlation Spectrometer

CVGHM (formerly VSI) - Center of Volcanology and Geological Hazard Mitigation

CVO - Cascades Volcano Observatory (USGS)

GMS - Geostationary Meteorological Satellite

GOES - Geostationary Operational Environmental Satellite

GVO - Goma Volcano Observatory

GVP - Global Volcanism Program (Smithsonian Institution)

HVO - Hawaiian Volcano Observatory (USGS)

ICE - Instituto Costarricense de Electricidad (Costa Rica)

IG - Instituto Geofísico (Ecuador)

IGNS - Institute of Geological and Nuclear Sciences (New Zealand) - now GNS Science

INETER - Instituto Nicaragüense de Estudios Territoriales (Nicaragua)

INGEMMET - Instituto Geológical Minero y Metalúrgico (Peru)

INGEOMINAS - Instituto Colombiano de Geología y Minería (Colombia)

INGV-CT - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (Italy)

INSIVUMEH - Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (Guatemala)

IRD - Institut de Recherche pour le Développement (France)

JMA - Japanese Meteorological Agency

KEMSD - Kamchatkan Experimental and Methodical Seismilogical Department

KVERT - Kamchatkan Volcanic Eruption Response Team

M - magnitude

METEOSAT - Meteorological Satellite

MEVO - Mount Erebus Volcano Observatory

MODIS - Moderate Resolution Imaging Spectroradiometer

MVO - Montserrat Volcano Observatory

MWO - Meteorological Watch Office

NEIC - National Earthquake Information Center

NIED - National Research Institute for Earth Science and Disaster Prevention (Japan)

NOAA - National Oceanic and Atmospheric Administration

NOTAM - Notice to Airmen

OVDAS - Observatorio Volcanologico de los Andes del Sur (Chile)

OFDA - Office of US Foreign Disaster Assistance

ONEMI - Oficina Nacional de Emergencia - Ministerio del Interior (Chile)

OVPDLF - Observatoire Volcanologique du Piton de la Fournaise (France)

OVSICORI-UNA - Observatorio Vulcanologico y Sismologico de Costa Rica, Universidad Nacional (Costa Rica)

PHIVOLCS - Philippine Institute of Volcanology and Seismology (Philippines)

RSAM - Real-time Seismic Amplitude Measurement

RVO - Rabaul Volcano Observatory

SERNAGEOMIN - Servicio Nacional de Geologia y Mineria (Chile)

SIGMET - Significant Meteorological Information

SNET - Servicio Nacional de Estudios Territoriales (El Salvador)

SVERT - Sakhalin Volcanic Eruption Response Team (Russia)

USAID - US Agency for International Development

USGS - United States Geological Survey

UTC - Coordinated Universal Time

VAAC - Volcanic Ash Advisory Center

VAFTAD - Volcanic Ash Forecast Transport And Dispersion

VDAP - Volcano Disaster Assistance Program (USGS)

VHP - Volcano Hazards Program (USGS)

VRC - Volcano Research Center (Japan)