Terremoto di magnitudo ML 2.5 del 18-12-2021 ore 22:40:35 (Italia) in zona: 1 km SW Belpasso (CT)

Un terremoto di magnitudo ML 2.5 è avvenuto nella zona: 1 km SW Belpasso (CT), il

  • 18-12-2021 21:40:35 (UTC)
  • 18-12-2021 22:40:35 (UTC +01:00) ora italiana

con coordinate geografiche (lat, lon) 37.5840, 14.9670 ad una profondità di 3 km.

Il terremoto è stato localizzato da: Bollettino Sismico Italiano INGV.

Ricerca terremoti: Qualsiasi nel raggio di 30 km

I valori delle coordinate ipocentrali e della magnitudo rappresentano la migliore stima con i dati a disposizione. Eventuali nuovi dati o analisi potrebbero far variare tali stime.

Visualizza la localizzazione con

Comuni entro 20 km dall'epicentro

Le distanze sono calcolate in base alle coordinate geografiche del Municipio (Istat).
Comune Prov Dist Pop Cum Pop
Belpasso CT 1 28108 28108
Camporotondo Etneo CT 4 5023 33131
San Pietro Clarenza CT 5 7743 40874
Paternò CT 6 48228 89102
Ragalna CT 6 3924 93026
Nicolosi CT 6 7463 100489
Mascalucia CT 8 31958 132447
Misterbianco CT 8 49410 181857
Motta Sant'Anastasia CT 8 12116 193973
Santa Maria di Licodia CT 8 7641 201614
Gravina di Catania CT 9 25838 227452
Pedara CT 9 14102 241554
Tremestieri Etneo CT 9 20589 262143
Sant'Agata li Battiati CT 10 9479 271622
Trecastagni CT 11 10910 282532
Biancavilla CT 11 24007 306539
San Giovanni la Punta CT 11 23060 329599
Viagrande CT 12 8563 338162
Aci Bonaccorsi CT 13 3524 341686
San Gregorio di Catania CT 13 11966 353652
Catania CT 14 314555 668207
Valverde CT 14 7840 676047
Aci Sant'Antonio CT 14 17984 694031
Adrano CT 15 36122 730153
Aci Catena CT 16 29851 760004
Aci Castello CT 16 18723 778727
Zafferana Etnea CT 17 9517 788244
Acireale CT 18 52622 840866
Santa Venerina CT 19 8592 849458

Città più vicine con almeno 50000 abitanti

Il terremoto è stato localizzato
14 Km a NW di Catania (314555 abitanti)
18 Km a W di Acireale (52622 abitanti)
65 Km a NW di Siracusa (122291 abitanti)
76 Km a N di Ragusa (73313 abitanti)
80 Km a NE di Vittoria (63339 abitanti)
80 Km a E di Caltanissetta (63360 abitanti)
83 Km a N di Modica (54633 abitanti)
84 Km a SW di Reggio di Calabria (183035 abitanti)
85 Km a SW di Messina (238439 abitanti)
86 Km a NE di Gela (75827 abitanti)
Sismicità recente e storica
Pericolosità sismica
Mappe di scuotimento
Mappa del risentimento sismico
Cronologia delle localizzazioni calcolate
Tipo Magnitudo Tempo origine (UTC) Latitudine Longitudine Profondità (km) Ora pubblicazione (UTC) Autore ID Localizzazione
Bollettino
Rev1000
ML 2.5 2021-12-18
21:40:35
37.5835 14.9673 3 2022-03-30
13:04:26
Bollettino Sismico Italiano INGV 99322691
Rivista
Rev200
ML 2.7 2021-12-18
21:40:34
37.633 14.946 4 2022-03-15
14:09:30
Sala Operativa INGV_OE (Catania) 98700261
Localizzazione e magnitudo preferite finora.
Parametri della localizzazione preferita

Localizzazione

Campo Valore
Tempo (UTC) 2021-12-18 21:40:35 ± 0.07
Latitudine 37.5835 ± 0.0036
Longitudine 14.9673 ± 0.0057
Profondità (km) 3 ± 1 (from location)
Metodo di valutazione manual
Stato della valutazione reviewed
Versione 1000 -> BULLETIN-INGV
Tipo di evento earthquake
ID localizzazione 99322691

Incertezze

Campo Valore
Tipo di incertezza uncertainty ellipse
Semi-asse maggiore dell'ellisse di confidenza (metri) 514
Semi-asse minore dell'ellisse di confidenza (metri) 246
azimuth dell’asse maggiore dell’ellisse di confidenza (gradi) 98
Regione di confidenza sul piano orizzontale espressa mediante singolo valore di incertezza (metri) 510.0
Livello di confidenza dell'incertezza (%) 68

Qualità

Campo Valore
Maggiore gap azimutale nella distribuzione delle stazioni all'epicentro 95
Numero di fasi associato indipendentemente se utilizzate nella localizzazione (determinazione dell'Origin) 75
Numero di fasi 75
Scarto quadratico medio dei residui di tempo risultanti dal calcolo del tempo origine (Origin) della localizzazione (sec) 0.34
Distanza epicentrale della stazione piu' vicina (gradi) 0.07734
Distanza epicentrale della stazione piu’ lontana (gradi) 1.93264
Numero di stazioni in cui l’evento e’ stato osservato 59
Numero di stazioni usate nel calcolo dell'Origin 59
Parametri delle magnitudo

ML:2.7

Campo Valore
Valore 2.7
Incertezza 0.2
Num. stazioni usate
Tipo di magnitudo ML
Localizzazione di riferimento 98700261
Agenzia INGV
Autore Sala Operativa INGV_OE (Catania)
Tempo di creazione (UTC) 2021-12-18 22:00:54

ML:2.5

Campo Valore
Valore 2.5
Incertezza 0.3
Num. stazioni usate 67
Tipo di magnitudo ML
Localizzazione di riferimento 99322691
Agenzia INGV
Autore Bollettino Sismico Italiano INGV
Tempo di creazione (UTC) 2022-03-15 14:09:17
Tempi di arrivo
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.CAR1.HHZ. 2021-12-18T21:41:08.16 0.3 undecidable manual P 30 214.5186 38 -1.59 22
IV.GRI.EHN. 2021-12-18T21:41:06.03 0.1 undecidable manual P 42 186.8685 38 -0.28 62
IV.PLAC.HHZ. 2021-12-18T21:41:02.43 0.6 undecidable manual P 53 160.4172 50 0.08 37
IV.SCIAC.HHZ. 2021-12-18T21:41:02.29 0.6 undecidable manual P 268 164.2134 50 -0.64 31
IV.FERC.HHN.00 2021-12-18T21:40:59.12 0.6 undecidable manual P 46 139.9488 50 -0.07 40
IV.JOPP.HHE. 2021-12-18T21:40:58.32 0.6 undecidable manual P 35 138.9609 50 -0.71 33
IY.OPPI.HHZ. 2021-12-18T21:40:56.48 0.6 undecidable manual P 50 118.5924 50 0.58 37
IV.IFIL.HHE. 2021-12-18T21:40:55.67 0.3 undecidable manual P 343 113.997 50 0.48 58
IV.IACL.HHZ. 2021-12-18T21:40:55.49 0.3 undecidable manual P 333 118.0929 50 -0.33 59
IV.CLTA.HHN. 2021-12-18T21:40:53.57 0.3 undecidable manual P 242 100.4217 50 0.48 59
IV.GIB.HHE. 2021-12-18T21:40:53.26 0.6 undecidable manual P 299 94.0392 50 1.15 30
TV.GMB1.HHE. 2021-12-18T21:40:53.63 0.3 undecidable manual P 48 99.0231 50 0.75 53
IV.SSY.HHN. 2021-12-18T21:40:52.91 0.6 undecidable manual S 169 48.1185 94 1.01 35
3D.OEM8.HHN. 2021-12-18T21:40:52.77 0.3 undecidable manual P 357 98.3238 50 0.01 66
IV.MSRU.HHZ. 2021-12-18T21:40:51.23 0.6 undecidable manual P 32 89.0442 50 -0.12 44
IV.PLLN.EHZ. 2021-12-18T21:40:51.57 0.6 undecidable manual P 302 85.3479 50 0.8 36
IV.RESU.HHZ. 2021-12-18T21:40:51.30 1.0 undecidable manual P 275 80.364 50 1.3 14
IV.CSLB.HHZ. 2021-12-18T21:40:51.61 0.3 undecidable manual P 296 88.9443 50 0.29 63
IV.IVLT.HHN. 2021-12-18T21:40:51.61 0.3 undecidable manual P 359 90.1431 50 0.1 65
IV.IVPL.HNE. 2021-12-18T21:40:51.30 0.3 undecidable manual P 1 87.9453 50 0.13 65
IV.CROCE.HHN. 2021-12-18T21:40:51.02 0.6 undecidable manual P 205 91.6416 50 -0.72 37
IV.IVUG.HHN. 2021-12-18T21:40:51.98 0.3 undecidable manual P 1 90.1431 50 0.47 60
IV.ISPIC.EHZ. 2021-12-18T21:40:50.80 0.6 undecidable manual P 184 89.244 50 -0.58 39
IV.MTTG.HHE. 2021-12-18T21:40:49.97 0.3 undecidable manual P 54 79.2651 50 0.13 66
IV.HVIT.HHZ. 2021-12-18T21:40:48.65 0.6 undecidable manual P 211 76.4679 50 -0.75 37
IV.HMDC.HHN. 2021-12-18T21:40:48.66 0.6 undecidable manual P 193 71.1732 50 0.07 45
IV.MPNC.HHZ. 2021-12-18T21:40:48.23 0.3 undecidable manual P 28 70.9734 50 -0.33 65
IV.MSFR.HHZ. 2021-12-18T21:40:47.27 0.3 undecidable manual P 327 59.7957 50 0.44 65
IV.RAFF.HHZ. 2021-12-18T21:40:47.82 0.3 undecidable manual P 233 66.6777 50 -0.07 69
IV.MCPD.HHZ. 2021-12-18T21:40:46.89 0.6 undecidable manual P 341 62.9925 50 -0.44 43
IV.HSRS.HHE. 2021-12-18T21:40:46.20 0.6 undecidable manual P 158 58.8966 50 -0.49 43
IV.MUCR.HHZ. 2021-12-18T21:40:45.18 0.1 undecidable manual P 351 51.6039 93 -0.34 89
IV.HLNI.HHZ. 2021-12-18T21:40:45.67 0.3 undecidable manual S 198 27.3504 96 0.95 56
IV.AIO.HHN. 2021-12-18T21:40:44.64 0.3 undecidable manual P 28 48.9177 93 -0.33 67
IV.EMCN.HHZ. 2021-12-18T21:40:44.03 0.6 undecidable manual S 14 23.754 97 0.57 44
IV.EPIT.HHE. 2021-12-18T21:40:44.71 0.6 undecidable manual S 17 26.4513 96 0.32 47
IV.SSY.HHN. 2021-12-18T21:40:44.54 0.6 undecidable manual P 169 48.1185 94 -0.28 45
IV.HVZN.HNE. 2021-12-18T21:40:44.85 0.6 undecidable manual P 206 50.1165 93 -0.37 44
IV.ESCV.HHE. 2021-12-18T21:40:43.50 0.6 undecidable manual S 324 22.5552 97 0.46 46
IV.ESVO.HHZ. 2021-12-18T21:40:43.03 0.3 undecidable manual S 355 21.0678 98 0.48 69
IV.ECNE.HHZ. 2021-12-18T21:40:42.70 0.3 undecidable manual S 9 20.3685 98 0.4 70
IV.EPDN.HHZ. 2021-12-18T21:40:42.73 0.6 undecidable manual S 12 20.6682 98 0.32 47
IV.GALF.HHZ. 2021-12-18T21:40:42.98 0.6 undecidable manual P 292 37.9287 94 0.2 47
IV.EMFO.HHZ. 2021-12-18T21:40:42.41 0.3 undecidable manual S 33 20.0688 98 0.23 73
IT.LNT.HGZ. 2021-12-18T21:40:42.01 0.3 undecidable manual P 175 32.8449 95 0.24 71
IV.ECTS.HHN. 2021-12-18T21:40:41.87 0.3 undecidable manual P 22 35.742 95 -0.47 67
IV.ECZM.HHZ. 2021-12-18T21:40:41.63 0.3 undecidable manual S 341 17.2716 100 0.38 70
IV.EFIU.HHN. 2021-12-18T21:40:41.40 0.6 undecidable manual P 43 31.2465 95 -0.05 49
IV.EMFS.HHZ. 2021-12-18T21:40:41.00 0.3 undecidable manual S 10 15.3735 101 0.43 70
IV.HLNI.HHZ. 2021-12-18T21:40:40.90 0.1 undecidable manual P 198 27.3504 96 0.22 96
IV.EPIT.HHE. 2021-12-18T21:40:40.29 0.3 undecidable manual P 17 26.4513 96 -0.2 72
IV.EMNR.HHZ. 2021-12-18T21:40:40.27 0.1 undecidable manual P 11 26.3514 96 -0.2 96
IV.EPOZ.HHZ. 2021-12-18T21:40:40.40 0.6 undecidable manual P 63 21.7671 98 0.84 40
IV.ESAL.HHN. 2021-12-18T21:40:40.32 0.3 undecidable manual P 38 24.0537 97 0.31 71
IV.ESPC.HHZ. 2021-12-18T21:40:40.57 0.3 undecidable manual S 24 13.1757 103 0.73 63
IV.EPZF.HHE. 2021-12-18T21:40:40.96 0.3 undecidable manual P 340 28.3494 96 0.09 74
IV.ESVO.HHZ. 2021-12-18T21:40:39.73 0.1 undecidable manual P 355 21.0678 98 0.3 95
IV.ESLN.HHZ. 2021-12-18T21:40:39.73 0.3 undecidable manual S 3 12.1767 104 0.22 74
IV.EMCN.HHZ. 2021-12-18T21:40:39.32 0.3 undecidable manual P 14 23.754 97 -0.63 65
IV.ECNE.HHZ. 2021-12-18T21:40:39.03 0.3 undecidable manual P 9 20.3685 98 -0.25 72
IV.ECHR.HNZ. 2021-12-18T21:40:39.69 0.3 undecidable manual S 337 12.3765 103 0.12 75
IV.ESCV.HHE. 2021-12-18T21:40:39.27 0.3 undecidable manual P 324 22.5552 97 -0.43 69
IV.EVRN.HHZ. 2021-12-18T21:40:39.13 0.1 undecidable manual P 52 18.87 99 0.15 98
IV.ECBD.HHZ. 2021-12-18T21:40:39.60 0.3 undecidable manual P 26 24.1536 97 -0.44 69
IV.EPDN.HHZ. 2021-12-18T21:40:38.78 0.3 undecidable manual P 12 20.6682 98 -0.56 67
IV.EMPL.HHZ. 2021-12-18T21:40:38.69 0.3 undecidable manual S 1 10.5783 106 -0.28 73
IV.ECZM.HHZ. 2021-12-18T21:40:38.33 0.1 undecidable manual P 341 17.2716 100 -0.35 95
IV.EMFO.HHZ. 2021-12-18T21:40:38.70 0.3 undecidable manual P 33 20.0688 98 -0.51 68
IV.EMFS.HHZ. 2021-12-18T21:40:38.00 0.1 undecidable manual P 10 15.3735 101 -0.28 96
IV.ESML.HHE. 2021-12-18T21:40:38.16 0.3 undecidable manual S 296 8.5803 109 -0.17 75
IV.EMPL.HHZ. 2021-12-18T21:40:37.13 0.1 negative manual P 1 10.5783 106 -0.23 98
IV.ESPC.HHZ. 2021-12-18T21:40:37.74 0.1 undecidable manual P 24 13.1757 103 -0.12 100
IV.ESLN.HHZ. 2021-12-18T21:40:37.40 0.1 undecidable manual P 3 12.1767 104 -0.27 97
IV.ECHR.HNZ. 2021-12-18T21:40:37.19 0.3 undecidable manual P 337 12.3765 103 -0.51 69
IV.ESML.HHE. 2021-12-18T21:40:36.67 0.1 undecidable manual P 296 8.5803 109 -0.31 97
Ampiezza e Magnitudo per ciascuna stazione
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.EMPL.HHE. ML:3.5 0.059001665 0.5248 AML other m 2021-12-18T21:40:39.37
IV.EMPL.HHN. ML:3.6 0.06869811 0.4608 AML other m 2021-12-18T21:40:39.65
IV.ESCV.HHN. ML:2.6 0.00286763 2.4064 AML other m 2021-12-18T21:40:44.46
IV.HLNI.HHN. ML:1.6 0.00025743635 2.9312 AML other m 2021-12-18T21:40:43.91
IV.ESCV.HHE. ML:2.4 0.0020593015 0.5632 AML other m 2021-12-18T21:40:43.79
IV.ESAL.HHN. ML:2.5 0.0022436265 0.32 AML other m 2021-12-18T21:40:44.09
IV.ESAL.HHE. ML:2.6 0.0025111029999999998 0.9216 AML other m 2021-12-18T21:40:43.65
IV.EPIT.HHN. ML:2.7 0.003092454 2.176 AML other m 2021-12-18T21:40:45.70
IV.EPIT.HHE. ML:2.7 0.0033423725 0.3968 AML other m 2021-12-18T21:40:44.77
IV.HLNI.HHE. ML:1.6 0.00023191899999999997 1.9968 AML other m 2021-12-18T21:40:44.82
IV.EFIU.HHN. ML:2.1 0.0006388635 1.344 AML other m 2021-12-18T21:40:45.70
IV.EPZF.HHE. ML:2.4 0.001403046 0.3456 AML other m 2021-12-18T21:40:45.93
IV.EPZF.HHN. ML:2.6 0.002324131 0.8448 AML other m 2021-12-18T21:40:46.34
IV.EFIU.HHE. ML:2.2 0.0007925869 0.448 AML other m 2021-12-18T21:40:46.64
IV.EPOZ.HHN. ML:2.8 0.0047799999999999995 1.22 AML other m 2021-12-18T21:40:47.21
IV.EPOZ.HHE. ML:2.9 0.00564 0.62 AML other m 2021-12-18T21:40:50.02
IV.EPOZ.HNE. ML:2.9 0.00626 0.6 AML other m 2021-12-18T21:40:50.03
IV.SSY.HNN. ML:2.1 0.0003731421 1.6256 AML other m 2021-12-18T21:40:51.96
IV.ECTS.HHN. ML:2.6 0.001515 0.72 AML other m 2021-12-18T21:40:51.22
IV.MUCR.HHN. ML:2.2 0.0003800292 0.4352 AML other m 2021-12-18T21:40:51.95
IV.ECTS.HHE. ML:2.4 0.0011665 0.8 AML other m 2021-12-18T21:40:51.57
IV.SSY.HHE. ML:2.4 0.00078725715 1.0752 AML other m 2021-12-18T21:40:51.49
IV.SSY.HNE. ML:2.1 0.00032845650000000004 1.3568 AML other m 2021-12-18T21:40:52.92
IV.MUCR.HHE. ML:2.1 0.00030113655 2.176 AML other m 2021-12-18T21:40:52.79
IV.AIO.HHN. ML:1.9 0.0002413695 1.6128 AML other m 2021-12-18T21:40:52.31
IV.AIO.HHE. ML:2.1 0.00037906130000000003 0.832 AML other m 2021-12-18T21:40:53.18
IV.GALF.HNE. ML:2.0 0.000416 0.64 AML other m 2021-12-18T21:40:53.18
IV.GALF.HHE. ML:3.0 0.00396 0.76 AML other m 2021-12-18T21:40:53.19
IV.GALF.HNN. ML:2.1 0.0005064999999999999 0.7 AML other m 2021-12-18T21:40:53.61
IV.SSY.HHN. ML:2.7 0.0014631824999999999 1.4592 AML other m 2021-12-18T21:40:53.66
IV.EPOZ.HNN. ML:2.8 0.005 0.4 AML other m 2021-12-18T21:40:53.88
IV.GALF.HHN. ML:3.0 0.0034699999999999996 0.98 AML other m 2021-12-18T21:40:55.49
IV.RAFF.HHE. ML:2.0 0.00019804949999999998 2.2016 AML other m 2021-12-18T21:40:57.64
IV.HSRS.HHE. ML:2.3 0.00039150000000000003 0.86 AML other m 2021-12-18T21:40:57.30
IV.HVZN.HHE. ML:2.6 0.0010175000000000002 0.62 AML other m 2021-12-18T21:40:58.48
IV.MSFR.HHE. ML:2.2 0.000333 1.04 AML other m 2021-12-18T21:40:58.38
IV.RAFF.HHN. ML:1.9 0.00013069552000000002 0.5376 AML other m 2021-12-18T21:40:58.96
IV.HMDC.HHN. ML:2.1 0.0002314134 1.7536 AML other m 2021-12-18T21:40:58.09
IV.MPNC.HHN. ML:2.8 0.0010364999999999999 0.38 AML other m 2021-12-18T21:40:59.38
IV.HMDC.HHE. ML:2.1 0.0001906621 2.0736 AML other m 2021-12-18T21:40:58.50
IV.HMDC.HNE. ML:2.2 0.00023499614999999998 1.9584 AML other m 2021-12-18T21:40:58.56
IV.MPNC.HHE. ML:2.8 0.001195 0.44 AML other m 2021-12-18T21:41:00.50
IV.HMDC.HNN. ML:2.3 0.00030382955 4.992 AML other m 2021-12-18T21:41:00.58
IV.HSRS.HHN. ML:2.3 0.00043200000000000004 0.5 AML other m 2021-12-18T21:41:02.45
IV.HVZN.HHN. ML:2.5 0.0009274999999999999 0.74 AML other m 2021-12-18T21:41:02.29
IV.MSFR.HHN. ML:2.3 0.000459 0.44 AML other m 2021-12-18T21:41:03.29
IV.ISPIC.EHN. ML:2.4 0.0003050203 1.1392 AML other m 2021-12-18T21:41:04.52
IV.ISPIC.HNN. ML:2.4 0.0003326215 1.216 AML other m 2021-12-18T21:41:04.58
IV.CROCE.HHN. ML:2.1 0.00015596192000000002 1.6128 AML other m 2021-12-18T21:41:04.44
IV.CROCE.HHE. ML:2.2 0.00016455815 2.7136 AML other m 2021-12-18T21:41:04.44
IV.MCPD.HHN. ML:2.3 0.00037 0.58 AML other m 2021-12-18T21:41:04.51
IV.ISPIC.EHE. ML:2.5 0.00040300000000000004 1.26 AML other m 2021-12-18T21:41:05.70
IV.MSRU.HHE. ML:2.4 0.0003100296 0.768 AML other m 2021-12-18T21:41:05.59
IV.MSRU.HHN. ML:2.8 0.0007725 1.64 AML other m 2021-12-18T21:41:05.14
IV.MCPD.HHE. ML:2.3 0.0004025 0.9 AML other m 2021-12-18T21:41:10.59
IV.IFIL.HHE. ML:3.3 0.001744799 0.3456 AML other m 2021-12-18T21:41:13.31
IV.PLLN.EHE. ML:2.9 0.001032 0.68 AML other m 2021-12-18T21:41:13.19
IV.IACL.HHE. ML:2.8 0.00048714195 0.8704 AML other m 2021-12-18T21:41:13.70
IV.PLLN.EHN. ML:2.9 0.001008 1.38 AML other m 2021-12-18T21:41:15.20
IV.IACL.HHN. ML:2.9 0.000634 0.6 AML other m 2021-12-18T21:41:17.72
IV.JOPP.HHE. ML:2.5 0.000186 0.3 AML other m 2021-12-18T21:41:18.22
IV.IFIL.HHN. ML:3.0 0.000905 1.4 AML other m 2021-12-18T21:41:18.73
IV.JOPP.HHN. ML:2.6 0.000235 1.34 AML other m 2021-12-18T21:41:19.14
IV.PLAC.HHE. ML:2.6 0.000184 0.9 AML other m 2021-12-18T21:41:31.09
IV.PLAC.HHN. ML:2.6 0.0001875 0.6 AML other m 2021-12-18T21:41:32.60
IV.CAR1.HHE. ML:2.8 0.000154 0.48 AML other m 2021-12-18T21:41:35.24
IV.CAR1.HHN. ML:2.7 0.0001365 0.42 AML other m 2021-12-18T21:41:37.06
TDMT - Time Domain Moment Tensor
Meccanismi di sorgente sismica nell'area
Download
Tipo Descrizione Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download
Forme d'onda Segnali sismici in formato miniseed + resp Download