Tephra segregation profiles based on disdrometer observations and tephra dispersal modeling: Vulcanian eruptions of Sakurajima volcano, Japan

Earth, Planets and Space

Table 1 Eruptions used for analysis

ID	Eruption onset (JST)	Plume height (km avl)	Dispersal direction	Working site	Detected site	Ejecta (10³ kg)	Wind speed (m s⁻¹)
18149	2018/5/10 19:22	2.8	S	10	5	9600	10.1
18216	2018/5/27 5:58	1.6	W	11	3	2600	4.5
18223	2018/5/29 3:34	2.5	T	11	6	13700	8.1
18231	2018/6/2 11:30	1.7	SW	12	4	11700	5.0
18242	2018/6/9 21:27	2.5	T	12	5	16600	6.5
18254	2018/6/16 7:19	4.7	W	12	4	47100	4.4
18270	2018/7/9 11:49	1.3	NW	13	3	10200	5.2
18277	2018/7/16 15:38	4.6	SW	12	3	16500	11.0
18288	2018/7/27 17:14	1.5	S	12	4	9500	3.3
18294	2018/8/1 17:39*	1.6	NW	12	4	3800	12.2
18418	2018/11/27 9:01	1.5	NE	12	5	3900	3.9
18456	2018/12/20 8:44	1.9	T	13	4	6000	3.8
18477	2018/12/25 20:21*	2.0	E	13	5	900	2.9
19079	2019/6/13 9:21	1.5	W	17	5	700	18.1
19090	2019/7/28 17:25	3.8	NE	17	4	13400	3.1
19092	2019/9/3 15:49	1.9	NW	16	3	1200	5.0
19099	2019/9/17 17:44	1.4	SW	15	6	9600	5.8
19102	2019/9/18 2:07*	1.8	T	16	5	9300	7.3
19115	2019/9/18 21:50	1.2	SW	15	6	700	5.6
19122	2019/9/21 6:09*	1.6	NW	15	3	2600	8.3
19127	2019/10/9 1:31	2.6	S	15	5	2800	6.3
19129	2019/10/10 2:48	2.7	E	15	5	5200	8.2
19145	2019/10/14 20:25	1.2	NW	15	6	800	7.8
19147	2019/10/15 13:04	2.3	SW	15	5	17400	6.2
19148	2019/10/16 5:46	3.0	E	15	4	2800	4.1
19168	2019/10/23 7:56*	2.3	T	15	5	400	4.1
19905	2019/11/4 17:58	2.4	SE	15	8	16600	5.4
19298	2019/11/20 18:26	1.8	S	14	6	17500	3.1
19301	2019/11/21 15:00*	1.0	W	14	5	11500	5.0
19302	2019/11/21 17:45	2.7	T	14	6	20100	4.2
19305	2019/11/23 0:43	1.8	W	14	5	5600	7.6
19306	2019/11/23 5:41*	1.3	W	14	4	9100	5.9
19309	2019/11/23 16:09	1.1	NW	14	4	10400	3.4
19310	2019/11/23 22:17	1.9	NE	14	6	5800	5.4
19311	2019/11/24 14:48	1.4	NW	14	3	9100	5.5
19323	2019/12/1 1:55	1.8	E	14	4	6000	7.5
19352	2019/12/10 19:29	2.5	NE	14	4	6900	2.1
19365	2019/12/15 2:25	2.4	E	14	4	3600	7.6
19393	2019/12/24 13:00	2.7	SE	15	6	8500	6.7

The ID number assigned to each eruption was created as follows. The first two digits correspond to the last two digits of the year when the eruption occurred and the last three digits correspond to the number in the annual JMA catalogs. The eruption onset is presented in Japan Standard Time (JST; UTC + 9). For the eruptions for which the time is marked with an asterisk, the end of the analysis period was set to two hours after the onset. A direction of “T” indicates that the plume moved steadily upward. The ejecta is the sum derived using the method mentioned in Sect. “TSP time series and TTDM calculations”. The wind speed is the mean value of the wind speed between the altitude of the vent and the top of the plume at the horizontally nearest grid to the vent. “Working site” is the number of the sites that were working during the eruption and “Detected site” is the number of the sites that detected tephra-fall