/. ( **3) / +33 *2 **2 + 2 **3 3 + An Empirial Relationship between Ground-surfae emperature and Heat-disharge Rate on Steaming Ground: Field Experiments Using IR hermometer and Ie Box Calorimetry Higashi U CHIDA akahisa S AO akatsugu YAMASHIA and Akihiko ERADA he heat balane model an be used to readily alulate the total heat-disharge rate through steaming ground based on the distribution of surfae temperature obtained by an infrared radiation (IR) thermometer. his method is onvenient ; however the model involves some ritial assumptions and large unertainties. With the aim of developing a simple method for reliable measurements of the total heat-disharge rate we arried out field experiments at the geothermal field of Yoshioka hot springs Aso volano Japan. o diretly measure the heat-disharge rate at eah measurement site we used Ie Box Calorimetry (IBC) whih an be used to measure the ombined ondutive and onvetive heat-disharge rate Q (W/m ) from the ground surfae based on the time required to melt ie housed within an aluminum box plaed on the ground. At the same time we used an IR thermometer to measure the ground-surfae temperature ( ) at eah site. Our observations revealed the relationship between the heat-disharge rate anomaly Q ( Q Q* ) and the temperature anomaly ( *) where Q* and * were the average ground-surfae temperature and the average heat-disharge rate outside the geothermal area respetively. Although the obtained data show a degree of satter the value of Q inreases almost linearly with onsistent with the heat balane model: QC where C is the proportional oe$ ient whih is estimated to be /+ (W/m / ) from the least squares method. We onsider that this empirial relationship is appliable in obtaining aurate estimates of the total heat-disharge rate from steaming ground. o assess the reliability of the linear relation and determine appropriate values of C it would be neessary to ondut additional aurate simultaneous observations of Q and at sites on many di# erent volanoes and under various meteorologial onditions. Furthermore we arried out measurements when the ground surfae was wet due to rainfall. As a result we obtained Q* of * W/m larger than the value obtained with a dry ground surfae. his experiment suggests that the presene of rainwater enhanes heat onvetion inluding latent heat near the ground surfae. Key words : steaming ground Ie Box Calorimetry IR thermometer heat-disharge rate ground surfae temperature 32- *2. + - +/ 203 +.*. /2* Sendai Distrit Meteorologial Observatory Japan Mete- orologial Ageny (JMA) +-+/ Gorin Miyaginoku Aso Volanologial Laboratory Kyoto University /2* Sendai 32- *2. Japan. Kawayo Minami-Aso Kumamoto 203 +.*. Japan. 2+* **/ + -0 : -11 +1++ 0.+ -0 Fukuoka Distrit Meteorologial Observatory JMA Present address. Volani Fluid Researh Center + -0 Oohori Chuo-ku Fukuoka 2+* **/ Japan. okyo Institute of ehnology 0.+ -0 Kusatsu Gunma 203 03/ /*. + -11 +1++ Japan. Aso Loal Cooperative O$ e for Volani Disaster Corresponding author: Higashi Uhida Mitigation JMA /*. + Miyaji Ihinomiya Aso Kuma- e-mail: h-uhida@met.kishou.go.jp moto 203 03/ Japan.
200 + **/ 0/ g +** g IBC **. m *-*. m **-. m IBC Q erada et al. (**2) IBC Q IBC **1 IBC (Matsushima S * **-) t m Q (Harris and Maiejewski *** ; Italiano and Nuio +33 ) ml Q ts / L --.. +* Jkg + Q Q Q t m Q ml Q ts +32* ; Sekioka and Yuhara +31. Q **- ; Sekioka +32- IBC QQQ erada et al. (**2) **. Ie Box Calorimetry ; IBC (erada et al. **2) *2. mm *+. m **3. Benseman +3/3 ; Hohstein and Bromley m +.*2 +* m *. *. m
201 Fig. +. (a) Loality and topography of Aso volano in entral Kyusyu Japan. (b) Loation of the Yoshioka hot springs and neighboring geothermal areas of Yunotani Jigoku and arutama. he solid square indiates the Aso Volanologial Laboratory (AVL) Kyoto University. **2 3 / 3 -* Q +- C G Y X (Fig. ) C X Y IBC Q Q IBC Q -+ IBC G Q IBC G 2 kwm IBC Q Y X Q (Figs. -) Y G **2. m X +* m Y / m 0 m (Hohstein and / Y+ Y0 Bromley **/) X+ X/ Q ++ * Q Q + + ++ Q + + Q + m - - X/ (Fig. + ) C (Fig. ) C A B b Q **0 (erada X Y +2 and Sudo submitted) C. - IBC Q m GARMIN GPS +* +*
202 Fig.. Aerial photograph of the Yoshioka hot springs at Aso volano Japan taken on 2 Otober **2. he lines X and Y drawn aross the steaming ground C orrespond to lines X and Y in Fig. -. (Fig. -) X. Q Fig.. a X. Q s -- t + + g Q Q Q */. * m Q Q Q Q* - IBC Q * * Q Q * * NEC NEC Avio Q Sekioka and H3+** PMV Yuhara ( +31. ) 2+. mm Q X * * + m Y C Q Q + m Fig.. b - + Q *
203 Fig. -. Spatial distribution of IBC (Ie Box Calorimetry) measurement sites (see Fig. for loation) and obtained geothermal heat fluxes Q (W/m ) and Q* (W/m ). he ground-surfae temperatures ( ) and * ( ) were measured using an IR thermometer. Q* and * are the values observed outside of the geothermal field. ( ) represents the temperature at +* m depth as obtained from a thermistor. +* + Q */. m Q - - * C X Y IBC. Q.+ t C -3* 33* 00.. 30 + ms m g /. g -0 g
204 Fig... (a) Example of the plaement of ie boxes at the site X.. o measure Q Ie Box A was plaed on the ground surfae. o estimate Q we plaed Ie Box B on a thermal insulation mat lose to the original measurement site (A). (b) Infrared image of the area around Ie Box A. he ground-surfae temperature at X. was estimated to be.. 1 whih was the mean temperature under the white line indiated in Fig..(b). t Wm /3* Wm (Fig. -) 3-2 m 2 g.-. Fig. -- Fig. - IBC Q + g Q s Q ( QQ) Q +-..+1 Q + g C s C Y- +.* Wm *.. Y X + +* m + X - ** Wm + s X. 1 Y- Fig.. b Y+ X/ IBC + m * (Fig. -) (Fig.. b) X- + X+ - +* m 3 /*
205.. C Q (Fig. -) * * -. 1 -.* -. 1 +* m /.. +*. + IBC t m + /0* 2 g +* t +-2* m - g.* g Q* +0* Wm +3* Wm Fig. /. Plot of geothermal heat fluxes anomaly Q -** Wm Q* Q* * (W/m ) versus ground-surfae temperature anomaly Wm * ( ). Open irles indiate the data obtained -.. at an area loated outside of the geothermal field../ he solid line indiates the best-fit line obtained using the least squares method taking into aount Fig. /. data olleted within the geothermal field. he Q arrow indiates the air temperature at the time when the observations on the geothermal field + g were arried out. he horizontal and vertial dashed lines indiate Q* Q of * W/m and * of -.. respetively. /+ Wm Fig. / * Wm Q / / + (IBC) Q (Fig. **0 C Q /) +2 C Fig. / X- Q * C - IBC Q Q Q + m Fig. /
206 IBC Q +* Wm *** X+ Y0 Q +* Wm t t m 1 g m -- g.- g Q 3* Wm -* Wm / IBC Q +/* Wm -* Wm IBC * Wm IBC IBC - km ; Fig. + IBC Q ( QQ) -* IBC Q **2 +* * +/ +0 -* Sekioka and Yuhara ( +31. ) **- 1* - ms +* m *. 2 IBC Q + Q *. (Fig. /) + Q. /- Q. Q.* Wm QC. +* Wm Sekioka and Yuhara ( +31. ) 2* Wm Sekioka Q and Yuhara ( +31. ) t C /+ + 0* +..* m -0 g./ g Wm Sekioka ( +32- ) +130 Wm t + ** m -3 g. Bowen +* + g /. *3/. Sekioka Q -* Wm ( +32-) C -3 Wm
207 C +-. erada et al. (**2) *** C 1- Wm Q* * C + /** m Q( Q Q* ) ( IBC ) Q IBC Q Benseman R.F. ( +3/3) he alorimetry of steaming ground in thermal areas. J. Geophys. Res. 0. +- +0. ( +32* ) C +- 1. (Seki- oka and Yuhara +31. ) IBC (**.) Q +- 1. Harris A. J.L. and Maiejewski A. J.H. (***) hermal surveys of the Vulano Fossa fumarole field +33. +333 : evidene for fumarole migration and sealing. J. Volanol. Geotherm. Res. +* ++3 +.1. (**-) 0 C **- CD-ROM V *// *.. Ie Box Calorimetry ; IBC Q Hohstein M.P. and Bromley C. J. (**/) Measurement of heat flux from steaming ground. Geothermis -. +-+ +/2. Hetty riastuty ( **1) **0 Q* * /* B -.3-/1. Q* * Wm Italiano F. and Nuio P.M. ( +33 ) Volani steam Q C C /+ Wm C +** m + + +* m **. (Oppen- heimer and Rothery +33+ ) IBC + +* m *
208 output diretly measured in fumaroles: the observed var- surfae. J. Geophys. Res. 13 */- */2. iations at Vulano Island Italy between +32- and +321. Bull. Volanol. /. 0-0-*. (**.) * 013+. Matsushima N. (**-) Mathematial simulation of magmamonitoring erada A. Kagiyama. and Oshima H. (**2) Ie Box hydrothermal ativity assoiated with the +311 eruption Calorimetry : a useful method for estimating heat disof Usu volano. Earth Planets Spae // //3 /02. harge rates through steaming ground. Earth Planets Oppenheimer C.M.M. and Rothery D.A. ( +33+ ) Infrared Spae 0* 0331*-. of volanoes by satellite. J. Geol. So. London +.2 /0- /03. Sekioka M. ( +32- ) Proposal of a onvenient version of the (**2) V +/+ *+3. heat balane tehnique estimating heat flux on geother- erada A. and Sudo Y. (**3) Geothermal ativity within mal and volani fields by means of infrared remote the western slope geothermal zone of Aso volano Japan : sensing. Memoirs of the National Defense Aademy Japan development of a new geothermal field in **0. Geo- - 3/ +*-. thermis submitted. Sekioka M. and Yuhara K. ( +31. ) Heat flux estimation in geothermal areas based on the heat balane of the ground