  /*  (,**/)
 -  +3/ῌ,*+   ,**.  3  +    , ,**.

+*+-

  ,**/.

3



Asama Explosion of September +st, ,**.On the Damage toGlass Windows and Estimation of Explosion Energy
Akihiko YOKOO,, Fukashi MAENO and Hiromitsu TANIGUCHIAt ,* : *, JST on September +st, ,**., Asama volcano erupted and produced a strong air wave (,*/ Pa at 1.0
km away from the summit). The wave induced some damages to glass windows in buildings located within about++ km of the summit. The detailed situations about these damages are reported in this paper. The explosion
energy of this eruption and diameter of crater are estimated to be +..+*+,,.,+*+, J and about 1/ m,
respectively, based on the assumption that scaling laws obtained by charge explosion experiments were applicableto the case of explosive volcanic eruption.
Key words : Asama volcano, air wave, glass breakage, explosion energy

TWij3k$ lmnMopO q](/V+   ,,/02m  !"#$%&'()&#

0r-"T@ /01XYZH[) /01M '"T $s12t"uvwx-d&*+,-./01 2345(Baker et al., +32-)

6-7 3 8$9:

"AK4{$! +33+@ +3/*;< =<+3-* ; >?

#-/01"ABC

Sakuma (+3/+) *&DE!F

@ xD& ##*y>z3/01|}-5~"_*-d#67fHfM !

# !G#H

8OF(TV$ :F #MJP

/01IJ/01KLMN$OFP@ +31- VFMJV'P"ABC$' $#*%Q&/01'9R(>?!

9lmn:'((TV(+31-) SOF(T@ ' ' UV- U*W"X8-dW@ VJ Taniguchi (+33-) H  ;YZ DP U*W"[)/01M\FP(,***) !M<'(T*W #

T]P^"_*$`a+b'(T*c,d

=$T #fAK4{$D&"T@ VF e]PV-"

7 #7fx"M5~" ¡¢x'-#fAR(. ! g/01Md]Ph  ¥32*ῌ2/12 ¦>§¨?©ª«¨? 0ῌ@A5¬5¬­ ¬lm®%¬¯°
Institute of Mineralogy, Petrology, and EconomicGeology, Graduate School of Science, Tohoku University, 0ῌ-, Aramaki-Aza-Aoba, Aoba-ku, Sendai
32*ῌ2/12, Japan.
 ±<B : ¥23+ῌ+.+3 ²³C§´CD +1,,ῌ+3µE5¬7flm<FB#¶3lm·¸¹
Present Address : Sakurajima Volcano Research Center, Disaster Prevention Research Institute, Kyoto|V(£¤!F*W@ V--*c-  ,**.

3University, +1,,ῌ+3, Sakurajima-Yokoyamacho, Kagoshima 23+ῌ+.+3, Japan.
 ¥32*ῌ2/10 ¦>§¨?©ºG .+@A5¬@A»¼»lm·¸¹Center for Northeast Asian Studies, Tohoku University, .+, Kawauchi, Aoba-ku, Sendai 32*ῌ2/10,Japan.
Corresponding Author : Akihiko Yokooe-mail : yokoo@svo.dpri.kyoto-u.ac.jp¶· ¸¦ ¹º:»¼196

 +     !"#$%&'3+$()*+,-./0 1z{|}^'_1567~C]^'_abc$ `- d$  (Fig. +) :' ,  `A  D d $8

,*,, (0-., Pa), 1.0 km ]O,ῌ ῑ῎ῐ ,**. ΐ 3 ῏ + ῒ῔῍ ,*/ Pa  1 f<] ,**. 2 3  +  ,* 3 *, 4 567879:!

567N$ +0 $ -/* bZ

;<' 7=>? @ABCD  !  $ '^$

¡FG

7EFGHIJK$L'MN7OP7QRC

8 PPI¢ !$£%MNo¤¥

D 1 3  + $ST8 +U+*/ t VWXY`¦§ ,**/d1 !o¨©ª bu$Z[\C]^'_ `abc ,**.d1 e$f 3 gh 7EFGy«'Z©¬8 3* km V] m­

8:ijk^l mnopqC]_r `st®X_1 3  + $¯°8 ±Z²r!

uv ,**.d ,**. 2 +* wxy5678z³FY ¦´$ +32, 2$y$ `µ  +32,dFig. +. Disaster distributions around the Asama Volcano by the September +st eruption. Six places su#ered fromthe air wave ; damage to glass windows (open circles) and others (closed circles). Three squares represent thevolcano-acoustic stations equipped with a low-frequency microphone by the Japan Meterological Agency, andthe star shows the location where 1 ballistic rocks were discovered by our investigation.

g¥. ,**.  3  + 

8YZ[f¢!=4º»g¼KXI+31-    +31-   

197

4z{|}( S~J {J`KITaU 6E (Table +)
.8YZ[9:VW" <_ 
32



,.1 km !" #$% (Fig. +)  /&+* cm  1 '()

TaXIL6VE]^3 (Taniguchi,+33-) "K)-El -0&-1/ g * $"+ ,3 (Saito et al., ,**+)  Table +  -./01 (SiO, 2/3.1&0*.+ wt.ῌ) 3\ YZ[9:LEW`KIa=P" + 4"5$6  7, 83'Y(V6 8YZ[9:*U$<9%" #$ . km :;_ B67`KIa(XIE"Z[\< !=   ,**. 3 >  3n\ * ^6

9% <:""#3 $? ,**-  0i` +*  ,**.  3  -n YZ[9:b0(cd|*" @A

B%C&(DE #$ +.0 km F:;" + m '(GH)
+IJKLK* HM  * N",-OP./QHi,- ]^_a\Ke3*1]^$ -ῌ,33++ "e 6 - ¡B6

 R+0S13 2T <*U"3

8YZ[9:f¢-£  >\¤ , ¡ gVW6¥.h^¦ijk§¨ 6 2*U(0 R- -ῌ+ lW©!( ª + ¡ g¥om¦ 6"«¬­LE®e¯K°!(4 65X> t z±  $ .n$ ,* km o²B678YZ[9:\;(]^G" <_6|} p e3lW©!(B67

8YZ[9: + ¡ qq ++ km r60

`KIa= >a= (bpc) defg[ (I2hb*W  ;  cdJ8YZ[9:"³

pc (t) dt)  ?  ( ] ^  @ A  3   6 B67´µs#ῌt¶ + ¡(Baker et al., +32-) $ YZ[BCijdk 3

u 0 km 88D$"+ wv + ¡ 

"8D E%FG*UlYZ[9:E

u 1./ km -6 *w#Am(H^*6 *n 'opq%8DiE%FG*UIJKrS1s; 6 R * $p(Fig. +)

-ῌ,ῌ+ 

#$%u . km 3g¥.h^¦" (Fig. +) B67 + ·xs#YZ[q> t YZ[9:L6lMNuH6+ y9: 9: YZ[z"3; <*(vOJ#$E*"W6 >¸ ^{ % /* cm M <R YZ[9:WP6 4wxiQyR

Table +.

(Fig. ,a) h^¦|<­}¹" Z¸< ~"<_YZ[Relationship between the overpressure and damage to glass windows.

<uvw$` xl4»¼198)L-._ +,*ῌ+/* cm '(`*/a% b$

BTU++** mm:11* mm:- mm  c1 S * ,"-.( d&e 0*/  LP<0f1631 9 , g'h9'( (Fig. ,b)-ῌ,ῌ- $iM,2j Yk"h342- ;5_ . km, Fig. +> 65.?@ABCDO7+_0 cm 81l 9m:h(Fig. ,c)  BTU+/./ mm:2**mm:0.2 mm  ?@ABCD_I;  EFnCopDqrprGstpuc1<= >v, ?% 9 w8% xy@z)31  A& 9m:h01c-]7





3 0 cm 2BC

D{C|G& ?@ABCD #D519z)31 ;+}Ej~FG 

H>

Fig. ,. Photos of (a) glass breakage at the Asama
Volcano Museum taken by Kyodo News, (b) aview from a broken window at Tashiro Primary
School and (c) a glass crack at the Asama
Memory House taken by M. Enomoto.

-ῌ,ῌ.

2I <= #MJ  %KL M51g *, ;N +,,// m> O >v 3JP+,,9

3   #M&9m QR% S-3  %% Tw8Z
&  JP,9 '



Uc%S  UVW  )c ;Sakuma, +3/+ ; XY     

KBZ[\M,] +33*>  +3,3 ^ Fig. ,a   !"#  $  % &'() 
*" +,," -.  -*/01

233 #M*,6.JKL 2 ! %

'_51 ;&`]a+3-*>   ,3`* d&e ++ km

45%6ῌ

KL Yk"`* ,78,-39 9m z)31



 J

3 Fbb x@&,*** mm:3** mm:/ mm ;! < =5>  ;%>   ?@ABCD EFDG@H. I51 $i -ῌ,ῌ, JKL  ¡G¢£cJPd¤¥¦§- e% %% f,dM,#M4 ++ km 2%

M¨©@ªG  g«51 M,m ;)¬ (Fig. +) - NOLP + NQR  + !

 ­#h/aI>

% "QRS' + !  #M$® M,BXk¯b° z)31

%&% % ;%> BTU+*0* mm:20* mm:- mm  ?@ABCDEF

DG@HI51 V,ῌ- '(% +/ cm:,* cm '( )WX 3 /* cm Y
Z*1 QR+,51 [\  Y ]Z-^¥Kij ;Taniguchi, +33- ; l4m ,***> e  `\f,±² ;³Gqpun> M,#M

op´q 'µ 3  + rM,#M
f,¨©@ªGs¶3  + r#M#·  F¸¸t90¹º ,**.  3 Q + R ·¸¹º»¼~}199

 *.  ,**.  !"#$% &'()*+,-. /01  +2+*/
t 345 ,**.

6789&':;,

&<=#>?@ABC9CD;,#E-.
&'()

F;GH +/**I+0** kgῌm- JG

K- =L-MNO)# 02+*. I12+*. m- 68=P-. 3 Q +0 R=STBU9VWX SAR YZ
# &<=[\]9^X_` abPBCc#def,Pg. ,# =LhCD;,>?@ABC9[\] ij +** m : STB
U ,**. =Lhk;,hX0lmn.
o 3 Q + R=LhCD;,>?@ABCH ij Dp+** qmr sG d qmr

t uvw

*+he-. K- o O) V qm-r #Vx

pdD,+,(+)

y;, ,H=L-MNO) 02+*.I12+*. mePK ij D sG dz{9|};,-

=P-. # Goto et al. (,**+) =L->?
@ij D ~ Eexp qJrz{logDx*.-,2logEexp,.*0H(,)

g- (Fig. -a) ij D +ῌ-qmῌJ r sG d H~ Eexp

csG d῍+ῌ- XhcX:   z{Xh Fig. -b =K-.
csG9 *.**. mῌJ+ῌ- _ gn (,)

H*+- =Lhij 1*I+** m JG >?@ABC9CD;, o  ~9 +.02+*+,I..12+*+, J };,-.
Baker et al. (+32-) # =- TNT ~Fig. -. The relationships between the crater diameter (D ; m) and (a) : Explosion energy (Eexp ;J) calculated using eq. (,), (b) : scaled depth ofexplosion (d῍ ; m/J+/-) under the assumption ofcrater’s volume ; Vx0.*2+*. m- and 1.*2+*.
m-, and (c) : ratio of energy partition for blastfrom explosion energy (eblast). Dashed lines in(c) are derived by applying the results from ﬁeld
explosion experiments (eq. (.)). See text indetails.

~

=/gh ~=Lh ;,-3 >
P qPar  c l῍ qmῌJ+ῌ-r  la) L1:©ª68«;g. ,# ¬@­qmr H~

X +.-2+*++ J gn# O ~+ῌ- cz{HXhg-. ,=L- >9 +*,I+*- Pa Eexp  ="®;, X¯°;,hl῍x,.*2P*.30 *.*1(-)

- ¡X Baker et al. (+32-)
def. 

= 345

>¥ (,*/ Pa) Hc l῍# +./, mῌJ+ῌ-Figure ,ῌ./ O ¢£¤;,K- ¦§B¢

P1 & O ¢0©!" /01 3H X

gPgl-.
m ~± ²³ (Goto et al., ,**+) };,-´"® e blast sG d῍ z{# *pd῍p*.*+c

=gheblastxexp *../1**2d῍(.)

9 1.0 km - 3 Q + R yK9 ~  csG9µP-

# (10**/+./,)- x+.-2+*++ J ¨):,-. X68´ "®9«;µP-. 3 Q + RX  ¥#;=}X~ Eexp (Fig. -=gh¶};,->?@ij D ºbcdpe/ p5o»¼

200

 dῌ  (Fig. -b) e blast+*. m-   +*.1  

0Fig. -c ! 

" D # $%&'(  ! )*+,-./ - 0123 # $%&4
 567 0123

8%&

9: ;< =>= ??  !  V @=A9ABC

"D#$%&

D A d *EFGH 2 dῌ (Fig. -b)/
#8%&4 IJ K (.) =B#LA57
0123  eblast # $%& ?< !

(Fig. -a) 5">:=B0123*5N=B012

M !>:=B0123
3 / >:

 eblast

Fig. -c O  OPIJ#Q+QR S

Fig. .. Relationships among scaled distance (lῌ ; m/J+/-), scaled depth (dῌ ; m/J+/-), and scaled
weight of ballistics (wῌ ; kg/J+/-) with an empirical limit of the maximum scaled distnace ofballistics (broken line). These bubbles are resulted from several charge explosion experiments(1.. +*.v..1 +*1 J). This ﬁgure is modiﬁed
from Taniguchi et al. (,***).

!UV#"W+ 3 X + #Q

T

$%&& DY4

3 X + #QLA)

1.11 m S4 ?

>: . km > -,* g  *? >@ A

$Z0123 =A +.. +*+,,., +*+,/B C/ #~ A?DE=B

J #':!

" (Fig. -a) ?$ K (+) 4# .,./ m !

#N$B
mῌJ+ῌ-GH2!

(*.**-.*.**-/& (Fig. -b)& t< ??=BPK (,)(.) -OPIJF#<=A-2G HDA&:&# x$t^.=& B0123 3- !

)[\>:?0123

Eexp *+,DA]-^. /_OP

" EEI=JS9AS 9kQ+QK & SLA)[=B0`)[a1-)[2b3#4 -QL ¡¢t 56-IJ GH 2 dῌ$=AGH 2a1 lῌ GH 2b3 wῌ ckgῌJ+ῌ-d efg !=AA (Fig. .) Fig. . hijk)[LB>¡¢M£,GH 2$Z=B0`)[a1lm/ῌ ῍GH 2# *.**-*.**. mῌJ+ῌ- S"W+=AE4B4n

&IJ#':$?#9: A *5o p 6ῐ,**. N 3 X + # ,* ¤ *, ¥¦Q=+§¨©O¨56#ªP B ?56,***/ ? q 7': BGH 24 «pQ«R¬A . S­fGT (*.**-.*.**-/ m/J+/-) $Z)[lmU®#L=B ? :tQo>:n¯?<GH 2a1E *.*. mῌJ+ῌ- 89  ?
GH 2a10123

Eexp (+..

+* ,.,+,& ++ km a1S4 YB

V+WXC&S­fG#T=AY°SLB+*+, J : Fig. -a)  +ῌ- rrs? 3 X + #Q

OPIJ#Q+Q$T E ..// km :a1Y)[ Qo)YZ[±\²£= .23>:³T

IJ#':  t&u /_OP:´CA 0123 µLB :B;0123n ..1+* J )[21570123

3lm+* g S?>:)[a1lm *Fig. .

+..

/GH 2b3 ,.2+*v/ kgῌJ+ῌ- wx)[)[a1lm

2 */ $=A<yS DY4 ??9b3,.2+*v/|}#~=B=+*+,,.,

*+,?

+*+, J J#':B ?$..// km :~:O{)[a1DE=&>LB+ῌEexpz*.- kg S O{Qo>: ,.1 km a1S4 >?lma19A& YB Qo῏῎]$¶4^·{

"WQ+_2¸ `a8¹

lmb ,**. / 3 i + 03`¸EU-fD%¹º£»x¼    !"#$%  & '( ) +*"

,*"-  ./0 1

2"3/45.67 89:;<=>
%  ?= @A +;

BCD

EEBFG HIBC H,J K
+.*2*,*- BC!" : #MNOJ Lῌ ῏ ῎ ῍Baker, W. E., Cox, P. A., Westine, P. S., Kulesz, J. J. andStrehlow, R. A. (+32-) Explosion hazards and evaluation. Elsevier, Amsterdam, 2*1 p.
Clancey, V. J. (+31,) Diagnostic features of explosion
damage. 0th Int. Meeting of Forensic Sciences, Edinburgh.
Goto, A., Taniguchi, H., Yoshida, M., Ohba, T. andOshima, H. (,**+) E#ects of explosion energy and depth
to the formation of blast wave and crater : ﬁeld explosion
experiment for the understanding of volcanic explosion.
Geophys. Res. Lett., ,2, .,21ῌ.,3*.
PD$ (+323) %&QR'STU( VW%&XYZ[\] H^_`)a*J bc+ -.3ῌ-2/.
Kinney, G. F. and Graham, K. J. (+32/) Explosive shocks
in air. Springer-Verlag, New York, ,03 p.
de, (+31-) `b-f g. .2 / +h- i +-ῌ+ +,+p.
de, (+33+) 0 j`bk1 de, .2. p.
de, (,**.) lmb`bj2;<`b3`4567anopa7q de, -8%"r9 :s201+0 / 3 i 3 0;<t (,**.) usvMwxyxz={|lmb`M>}~}? ;<t ,**. /%"3 i ,* 0@ABCBC `bz= (+33*) `bD%3`{<EUF--f `b3`456a- .1 30ῌ+*,.
G WHIJWGKW#.WLW#MNO (,**/) 'F- lmb ,**. / 3i + 03`<d2MNI OPBC 3 ,.-ῌ,/,QG=RM (+3-*) lmbSEUF- - . +3-ῌ+30.
Saito, T., Eguchi, T., Takayama, K. and Taniguchi, H.
(,**+) Hazard predictions for volcanic explosions. J.
Volcanol. Geotherm. Res., +*0, -3ῌ/+.
Sakuma, S. (+3/+) Damage on window-panes by the airwaves of explosion of Volcano Asama on Sept. ,-, +3/*.
Bull. Earthq. Res. Inst., ,., 0*/ῌ0+/.
¡ W '¢lm`b *. /3`F-~£x¤(,**.) lm`b ,**. / 3 i + 03`3¥T¦ ;§a¨a©ªU« HVWJ S-..
Taniguchi, H. (+33-) Recent situation and plan for theexplosion energy estimation of phreatomagmatic explosion. In Proceedings of the International Seminar of Physics of Vapor Explosions, edited by M. Akiyama, ,0-ῌ,03.
#MNO W X +2  (,***) `bD%¬=¤­®]¯’33 +333 /G°D%±s²-f³ -3 p.
b YZ (+30+) D%EU ^_`) ,, .,ῌ./.
´[8µ (+32,) g. /1 / . i ,0 0 lmb3`de -*, +-ῌ+..
H*¶\] ·¡^J