Supplemen a y ma e ial o : Measu ing he elec ical cha ge
and se ling eloci y o olcanic ash pa icles
Allan F ies*1, Edua do Rossi1, Jona han P. Me ison2, Jens Jacob I e sen2, Ta sushi
Ma suyama3, F édé ic A laud1, Jona han Lemus1,4, Simon Thi e 1, Ca olina Diaz-Vecino1,
Ricca do Simiona o1,4, Cos anza Bonadonna1
1 Dépa emen des Sciences de la Te e, Uni e si y o Gene a
2 Depa men o Physics and As onomy, Aa hus Uni e si y
3 Depa men o Science and Enginee ing o Sus ainable Inno a ion, Soka Uni e si y
4 Dépa emen d’in o ma ique, Uni e si y o Gene a
* [email p o ec ed] [co esponding au ho ]
ORCiD (AF): 0000.0002.9060.1357
ORCiD (ER): 0000.0003.3749.5804
ORCiD (JPM): 0000.0003.4362.6356
ORCiD (JJI): 0000.0002.7879.6163
ORCiD (TM): 0000.000272719212
ORCiD (JL): 0009.0001.3644.0126
ORCiD (ST): 0000.0003.0836.6421
ORCiD (CDV): 0009.0002.4084.6484
ORCiD (RS): 0000.0002.1283.3136
ORCiD (CB): 0000.0002.2368.2193
TABLE OF CONTENT:
Supplemen a y Figu es
• Figu e S1: 3D iew o he p in ed ci cui boa d wi h he embedded cha ge ampli ie .
• Figu e S2: Schema ic ci cui diag am o he bipola o unipola con e e .
• Figu e S3: TTFCs used in ield and labo a o y expe imen s.
• Figu e S4: Schema ic iew o he cha ge ampli ie , bipola o unipola con e e and
connec ions wi h he A duino boa d o he au onomous e sion.
• Figu e S5: Celes on handheld digi al mic oscope images o he pa icles used in
labo a o y expe imen s A. E1-E12, B. E14 and E18, C. E16, D. and E13 and E17.
• Figu e S6: Su ace cha ge densi ies and cha ge o mass a ios o pa icles in
labo a o y expe imen s.
• Figu e S7: Su ace cha ge densi ies and cha ge o mass a ios o all he pa icles
de ec ed du ing ield expe imen s a Saku ajima and E na olcanoes.
• Figu e S8: Raspbe y Pi e sion o Vol Ash.
• Figu e S9: A mosphe ic pa ame e s associa ed wi h analysed e up ions.
• Figu e S10: G ainsize dis ibu ion o he sample collec ed in a ay a loca ion E2.
Supplemen a y Tables
• Table S1: GPS coo dina es o he ield loca ions
• Table S2: Lis o samples collec ed on adhesi e ape.
• Table S3: Schema ic iew o he cha ge ampli ie , bipola o unipola con e e and
connec ions wi h he A duino boa d o he au onomous e sion.
Supplemen a y Da a
• Da a S1: Ske ch o con inuous ol age measu emen s and da a sa e.
• Da a S2: Labo a o y expe imen s: desc ip ion o he di e en es s, high speed ideos;
ol age signals associa ed wi h he expe imen s.
• Da a S3: Field expe imen s: ol age signals eco ded du ing ield expe imen s.
• Da aS4: Measu emen s o he pa icle cha ge and eloci y a Saku ajima olcano.
• Da aS5: Measu emen s o he pa icle cha ge and eloci y a E na olcano.
Figu e S1 – 3D iew o he p in ed ci cui boa d wi h he embedded cha ge ampli ie . [A] Top iew. [B]
Bo om iew.
Figu e S2 – Schema ic ci cui diag am o he bipola o unipola con e e used in he au onomous e sion
o he ins umen .
Figu e S3 – TTFCs used in ield and labo a o y expe imen s, wi h co esponding ape u e diame e D and
leng hs L gi en below in mm.
Figu e S4 –Schema ic iew o he cha ge ampli ie , bipola o unipola con e e and connec ions wi h
he A duino boa d o he au onomous e sion.
Figu e S5 – Celes on handheld digi al mic oscope images o he pa icles used in labo a o y expe imen s
A. E1-E12, B. E14 and E18, C. E16, D. and E13 and E17.
Figu e S6 – A. Cha ge su ace densi y
𝝈
calcula ed conside ing indi idual pa icles in labo a o y
expe imen s a e sphe ical. B. Cha ge o mass a ios calcula ed o he elease o pa icle masses in
labo a o y expe imen s.
Figu e S7 – A. Cha ge su ace densi y
𝝈
calcula ed a Saku ajima and E na olcanoes conside ing he
objec s de ec ed in ield expe imen s a e sphe ical. B. Cha ge o mass a ios calcula ed o he same
objec s assuming a densi y anging om 750 kg m-3 o 2700 kg m-3 o Saku ajima, which co e s he ange
om pa icle clus e s o indi idual ash pa icles, and a densi y o 2800 kg m-3 o E na. The ange o
possible pa icle diame e s is calcula ed om he se ling eloci y using he equa ion o Baghe i and
Bonadonna (2016) (see e e ences in he main ex ), assuming a a ia ion in sphe ici y o 0.55 o 1.
Da a S1 – Ske ch used o ead ol age and sa e da a o he SD ca d. Modi ied om he “Read Analog
Vol age” example ske ch in he A duino Documen a ion (Las e ision No . 20, 2022 by Killaship).
/*
ReadAnalogVol age: Reads an analog inpu on pin 0, con e s i o ol age, and
p in s he esul o he Se ial Moni o .G aphical ep esen a ion is a ailable using
Se ial Plo e (Tools > Se ial Plo e menu). A ach he cen e pin o a
po en iome e o pin A0, and he ou side pins o +5V and g ound.
This example code is in he public domain.
h ps://www.a duino.cc/en/Tu o ial/Buil InExamples/ReadAnalogVol age
*/
// Lib a y o communica e wi h he SD ca d
#include <SD.h>
#include <SPI.h>
// Coun he iles on he SD ca ds o add a new ile wi h name da aXXXX wi h XXXX
he numbe o iles
File oo ;
in ileCoun = 0; // o coun ing iles
in loopCoun e = 0;
cha ilename[23]; // Decla e ilename in his scope
S ing olde Pa h = "/RESULTS/"; // Speci y he olde pa h
S ing accumula edDa a = ""; // Ini ialize a s ing o accumula e da a
// De ine he chip selec pin o you SD ca d module
cons in chipSelec = 10;
// he se up ou ine uns once when you p ess ese :
oid se up() {
// ini ialize se ial communica ion a 115200 bi s pe second:
Se ial.begin(115200);
delay(1000);
// Ini ialize he SD ca d
i (!SD.begin(chipSelec )) {
Se ial.p in ln("SD ca d ini ializa ion ailed!");
e u n;
}
// Lis iles in he oo di ec o y
File oo = SD.open( olde Pa h);
// Coun he numbe o iles a he oo o he SD ca d:
while ( oo .openNex File()) {
ileCoun ++;
}
oo .close();
// Gene a e a unique ilename he ile o w i ing
// Fo ma he ilename wi h he cu en coun e alue
// Gene a e a unique ilename wi h he olde pa h o w i ing
snp in ( ilename, sizeo ( ilename), "%sda a%04d. x ", olde Pa h.c_s (),
ileCoun );
// Open he ile
File da aFile = SD.open( ilename, FILE_WRITE);
i (da aFile) {
Se ial.p in ln("File opened success ully");
// Close he ile
da aFile.close();
} else {
Se ial.p in ln("E o opening he ile");
}
// Change he numbe o bi s o analog ead
analogReadResolu ion(14); //change o 14-bi esolu ion
delay(2000); //To a oid da a los , delay a pe iod o ime o wai o he
module o s a
}
// he loop ou ine uns o e and o e again o e e :
oid loop() {
loopCoun e ++; // Inc emen he loop coun e
// ead he inpu on analog pin 0:
in senso Value = analogRead(A5);
// Con e he analog eading (which goes om 0 - 16383) o a ol age exp essed
in mV (0 - 5000mV):
loa ol age = senso Value * (5.0 / 16383.0) * 1000;
// Accumula e da a in he s ing
S ing da a
= S ing(S ing(loopCoun e ) + ";" + S ing(millis()) + ";" + S ing( ol age) + " n
");
accumula edDa a += da a; // Add a newline be ween da a poin s
// Check i he loopCoun e is a mul iple o 750
i (loopCoun e % 750 == 0) {
// Open he da a ile o w i ing
File da aFile = SD.open( ilename, FILE_WRITE);
i (da aFile) {
// W i e he accumula ed da a o he ile
da aFile.p in ln(accumula edDa a);
da aFile.close();
accumula edDa a = ""; // Clea he accumula ed da a
} else {
Se ial.p in ln("E o opening da a ile");
}
}
delay(1);
}
