Bul Le Tin of the Global Vol Can Ism Net Work
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Bul le tin of the Global Vol can ism Net work Vol ume 28, Num ber 5, May 2003 Ana ta han (Mari ana Is lands) Nearly con tinuous ash plumes through May ....................2 Chiku ra chki (Kur ile Islands) Eruption contin ued through May; long plumes and some ash fall ........5 Karym sky (Kamchatk a) Fre quent ash plumes gener ated from Oc tober 2002 through May 2003 ........6 Har- Togoo (Mon go lia) Fu ma roles and mi nor seis mic ity since Oc to ber 2002 ..................7 Mayon (Phil ip pines) Three small ash- and- steam ex plo sions dur ing April- May 2003 ..............9 Karan ge tang (In do ne sia) Ash explo sions from January through May 2003 ..................10 Lokon- Empung (In do ne sia) In creased ex plo sive ac tiv ity dur ing January- April 2003; lo cal ash fall......11 Ruapehu (New Zea land) Steam plume issued from warm Crater Lake in May, but no erup tion ........12 Mon owai Sea mount (Ker madec Is lands) Volcanic earth quake swarm April-May detec ted by T-wave s ....13 Piton de la Fournaise (Réunion Island) Eruption on 30 May gener ates lava flows within Dolomie u crater ..14 Strom boli (It aly) Lava ef fu sion con tin ues through mid- June; in fra red sat el lite ob ser va tions .........15 Nyi ra gongo (DR Congo) 2002-3 lava lake activity, thermal ra diation, and CO2 and SO2 emis sions......16 Ro bledo (Ar gen tina) Sat el lite sur veys dur ing May 1996- October 2000 in di cate sub si dence ..........22 Utu runcu (Bo livia) De for ma tion de tected by sat el lite sur veys; low- level seis mic ity and ac tive fu ma roles...23 Sa ban caya (Perú) Infla tion at Hu alca Hu alca de tected by satel lite survey s from June 1992 to April 1996 ..23 Santa Maria (Gua te mala) La hars dur ing January- October 2002; ex plo sions and py ro clas tic flows......24 Ki lauea (Ha waii) Contin ued lava flows during De cem ber 2002- June 2003 en ter the ocean ..........25 Edi tors: Ed ward Venzke, Jen nifer Fela, Rick Wun derman, and Gari May berry Vol unteer Staff: Jac que lyn Gluck, David Char vonia, Rob ert An drews, Jessica Ball, and Ash ley McCleaf Global Vol canism Program · National Museum of Natu ral His tory, Room E- 421 · Washing ton, DC 20560- 0119 · USA Tele phone: (202) 357- 1511 · Fax: (202) 357- 2476 · Email: gvn@vol cano.si.edu · URL: http://www.vol cano.si.edu/ Subscrip tions are provided by the Ameri can Geo physical Un ion (see the box on the last page for details). Data are prelimi nary and sub ject to change; contact the original source or the Global Volcan ism Program bef ore using. 2 Ana ta han Smithsonian Institution — Bulletin of the Global stages of the erupti on, with one ash advi sory in dicat ing ash Ana ta han to 13.4 km alti tude on the 11th. At times multi ple clouds were mov ing in dif fer ent di rec tions at dif fer ent al ti tudes. Mari ana Is lands, cen tral Pa cific Ocean On 13 May Joe Kaipat from the CNMI Emergency 16.35°N, 145.67°E; sum mit elev. 788 m Manage m ent Of fice (EMO) and seism ologist Doug We ins All times are lo cal (= UTC + 10 hours) (Washing ton Uni versit y) flew to Sarigan (6.5 km W of Anata han) to retri eve seis mic data from a broadband instru - The ex plosive erupti on that began on 10 May is the first ment in stalled on 6 May. Records from the Sarigan stati on docu mented erup tion from Ana ta han in his tori cal time. showed increa sed seism icit y com mencing at about 1300 on There were no residents on the island due to their evacua- 10 May. The acti v ity re mained very strong for about 36 tion follow ing a shallow earth quake swarm in 1990 (Moore hours be fore de creas ing. and others, 1994), and another in 1993 (Sako and others, Ac tiv ity dur ing 13- 30 May 2003. A helicop ter over- 1995). Anata han is a com posit e volcano that erupts lavas flight on 13 May showed that the is land was still erupting, that are pri marily dac itic in compo si tion. It has the larg est but with less in tensit y than on 11 May. Large vol canic cal dera of the volca noes in the Com mon wealth of the bombs were ob served fly ing high in the air over the cra ter Northern Mariana Islands (CNMI). The presence of this region, and the whole W side of the is land was cov ered cal dera in di cates that large ex plo sive erup tions are pos si ble. with ash, in cluding the seism o graph site. The village ap- Strong acti v ity con tin ued over the next few days (Bul le - peared to have 15-30 cm of ash (fig ure 1). Ash advi so rie s tin v. 28, no. 4), with high ash plumes seen in satel li te im - for 13-14 May reporte d that a dense ash cloud was drifting agery. The area within ~ 55 km of the island was also W away from the island, but that it was not conti nu ous and placed off-li mits to all boats and aircraft not approved by varied in size. Ash plumes through 17 May gen erall y the CNMI Emergency Man age ment Of fice (EMO). A drifted NW or WNW. The erupti on clouds through May af - smaller but nearly conti nu ous erupti on colum n rose from ter the ini tial ac tiv ity were gen er ally be low ~ 6 km. the E cra ter of Ana tahan for the next sev eral weeks. Ac tiv - On 18 May the EMO group took an overfli ght ac com pa- ity was con tinu ing in early July, but at low lev els. nied by David Hil ton (Scripps Insti tuti on of Ocean og raphy) The EMO in vited USGS sci en tists to pro vide as sis tance and Tobias Fischer (Uni versit y of New Mex ico). They re- in track ing the vol cano’s ac tiv ity and as sess ing po ten tial ported a rising plume com prised of steam and ash. The hazards shortly af ter the erupti on began. USGS sci enti sts cloud was much lighter in color, with a reduced ash com po - first arrive d in Saipan on 30 May to work direct ly with nent com pared to the initi al phases of the erupti on. Bombs, EMO of fi cials to in stall and main tain moni tor ing equip- possi bly up to sev eral meter s in size, were being tossed into ment and inter pret data from overfli ghts and a single seis- the air; most fell back into the E cra ter. The ash was be ing mome ter op er at ing on Ana ta han. This sta tion be came op- blown W, but most of the ash fall was still on the E side of erati onal on 5 June. the island. The team landed on the E side of the island and Begin ning of the erupti on, 10-12 May 2003. On 6 May de ployed a PS- 2 seis mometer that ap pears to have re corded re search ers from Wash ing ton Uni ver sity, Scripps In sti tu- earth quakes and some tremor. At that site they found ejecta tion of Ocean og raphy, and the EMO aboard the MV Super thought to be from the initi al stage of the erupti on. The Em er ald deploy ed a seis mo graph on Anata han as part of a ground/vegeta ti on near and un der the ejecta was not joint US-Japa n Mariana Sub duc- tion Im ag ing Ex peri ment, which is funded by the Nati onal Science Founda ti on. There were no in di- cati ons of an im pending erup tion. During the night of 10-11 May the ship was again approach ing Ana ta han when sci en tists ob- served a trem endous lightning display ahead. As morning broke, they saw a pil lar of steam and ash bil lowing to an al ti tude of 9 km. The ship had to detour around the island to avoid the ash fall. Ini tial re ports in di cated that the erup tion began around 2100 on 10 May. Sat el lite data in ter- preted by the Wash ington Vol- canic Ash Advi sory Center (VAAC) showed that the erupti on appeare d to have started by 1730. An ash plume was clearly visi ble in im agery at 2232, result ing in an advi sory be ing issued to the avia- tion com mu nity at 2300 (1300 UTC). Plume heights were re- Figure 1. The village on Anata han covere d with ash, 13 May 2003. The recentl y deploye d seism o graph is barely ported to be 10- 12 km in the early visible in the clearing to the left.