Contents

Introduction
Preferred Moment Tensor Solutions for L'Aquila sequence
Other Earthquakes in Italy
Preferred Source Parameter Summary
Moment Tensors For Some Events using European Regional Waveforms
Moment Tensors Using ISIDE Data and WUS Model
Development of Velocity Model
Comparison of observed and predicted in different frequency bands - nnCIA,mod based on surface wave inversion
Comparison of observed and predicted in different frequency bands - ACI,mod based on surface wave and AQU receiver function inversion

Introduction

This page highlights the derivation of moment tensor solutions from a grid-search over strike, dip, rake and depth for the April 6, 2009 L'Aquila earthquake and its aftershocks. Within 10 minutes of the earthquake of the main event, the USGS NEIC estimate the moment tensor using the W-phase, and then later using the teleseismic body waves. Subsequently the USGS added CMT and regional phase solutions.

This web page documents the use of regional phase data, and especially the use of Italian digital data sets available from their ISIDE - Italian Seismological Instrumental e Parametric Date-Base by INGV) system.

We initially processed these data using precomputed Green's functions for the WUS model in order to focus on rapid source parameter determination. After becoming comfortable with the data sets, we used observed group velocities of Love and Rayleigh waves to modify a regional deep seismic sounding model. The new models were called CIA.mod, nCIA.mod and the final perferred model nnCIA.mod (Central Italian Apennines). Some features of the preferred model may be artifacts of the inversion, and will require further study, but this will not change the solutions very much.

The solutions to date are shown as a function of source depth in the next figure. The color scale at the right indicated the source depth. The size of the symbol is proporational to the moment magnitude of the earthquake. The moment magnitude is written at the top of the figure.

The moment tensor solutions are performed on the observed ground velocities in the the 0.02 - 0.10 Hz frequency band, except for the main event which was possible using the 0.01 - 0.03 Hz band. We prefer to use the ground velocity and as high a frequency band as possible since this provides a strong constraint on the velocity model.

Moment Tensor Solutions

Two sets of solutions are provided: those using regional waveforms from European stations and those using regional waveforms from the Italian Broadband Network which were obtained using the ISIDE - Italian Seismological Instrumental e Parametric Data-Base by INGV (preferred).

Since develping the CIA velocity model, we have also determined source parameters for other earthquakes in Italy. A map of the solutions given in the Preferred Source Parameter Summary
link is given in the next figure.

The inversion using the European waveforms appears at the USGS/SLU Regional Moment Tensor.

Inversion using ISIDE waveforms using nnCIA model (PREFERRED) for L'Aquila sequence

Focal Mechanism Map
Direction of maximum compressive stress and type of faulting: normal fault (red), strike-slip (green) and thrust (blue)
DATE TIME LAT LON H ML LOCATION FELT DETAILS
2008/10/01 22:47:37 42.590 13.287 15.4 3.1 Italy NO 20081001224737 Mechanism
2009/03/30 13:38:38 42.326 13.362 10.6 4.00 Italy NO 20090330133838 Mechanism
2009/03/30 13:43:26 42.303 13.364 9.9 3.50 Italy NO 20090330134326 Mechanism
2009/03/30 19:05:28 42.316 13.373 9.7 3.1 ITALY NO 20090330190528 Mechanism
2009/03/30 21:57:17 42.316 13.375 9.5 3.3 Italy NO 20090330215717 Mechanism
2009/04/03 04:44:42 42.327 13.358 9.40 3.00 Italy NO 20090403044442 Mechanism
2009/04/05 20:48:54 42.332 13.372 8.4 3.90 Italy NO 20090405204854 Mechanism
2009/04/05 22:39:41 42.341 13.380 8.5 3.50 Italy NO 20090405223941 Mechanism
2009/04/06 01:32:39 42.334 13.334 8.8 5.80 Italy NO 20090406013239c Mechanism
2009/04/06 02:27:46 42.374 13.342 10.0 3.90 Italy NO 20090406022746c Mechanism
2009/04/06 02:37:04 42.366 13.340 10.1 4.60 Italy NO 20090406023704c Mechanism
2009/04/06 03:56:45 42.336 13.387 10. 3.90 Italy NO 20090406035645c Mechanism
2009/04/06 04:08:45 42.376 13.356 10.0 3.0 ITALY NO 20090406040845 Mechanism
2009/04/06 04:47:53 42.352 13.347 9.4 3.70 Italy NO 20090406044753c Mechanism
2009/04/06 06:21:05 42.317 13.416 10.6 3.3 ITALY NO 20090406062105 Mechanism
2009/04/06 06:48:15 42.303 13.383 8.3 3.00 Italy NO 20090406064815 Mechanism
2009/04/06 07:17:10 42.355 13.367 9.2 3.90 Italy NO 20090406071710c Mechanism
2009/04/06 07:28:45 42.347 13.390 15.0 3.0 ITALY NO 20090406072845 Mechanism
2009/04/06 07:39:41 42.324 13.371 9.7 3.30 Italy NO 20090406073941 Mechanism
2009/04/06 08:40:13 42.364 13.366 10.6 3.20 Italy NO 20090406084013 Mechanism
2009/04/06 09:30:12 42.373 13.341 10.1 3.00 Italy NO 20090406093012 Mechanism
2009/04/06 09:47:02 42.264 13.393 10.0 3.00 Italy NO 20090406094702 Mechanism
2009/04/06 09:59:29 42.322 13.381 10.0 3.10 Italy NO 20090406095929 Mechanism
2009/04/06 10:36:18 42.343 13.402 10.1 3.50 Italy NO 20090406103618 Mechanism
2009/04/06 12:55:16 42.372 13.353 10.8 3.50 Italy NO 20090406125516 Mechanism
2009/04/06 14:14:38 42.365 13.338 10.6 3.20 Italy NO 20090406141438 Mechanism
2009/04/06 16:06:18 42.234 13.483 10.6 2.9 Italy NO 20090406160618 Mechanism
2009/04/06 16:38:09 42.362 13.333 10.0 4.00 Italy NO 20090406163809c Mechanism
2009/04/06 16:57:26 42.346 13.307 9.3 3.10 Italy NO 20090406165726 Mechanism
2009/04/06 17:40:04 42.376 13.334 10.8 3.00 Italy NO 20090406174004 Mechanism
2009/04/06 20:03:34 42.213 13.479 6.6 3.10 Italy NO 20090406200334 Mechanism
2009/04/06 21:56:53 42.396 13.323 9.7 3.80 Italy NO 20090406215653c Mechanism
2009/04/06 22:47:13 42.349 13.293 11.6 3.60 Italy NO 20090406224713c Mechanism
2009/04/06 23:15:37 42.4510 13.3640 8.0 4.80 Italy NO 20090406231537c Mechanism
2009/04/06 23:49:34 42.349 13.378 8.3 3.00 Italy NO 20090406234934 Mechanism
2009/04/07 01:52:03 42.432 13.393 1.2 3.00 Italy NO 20090407015203 Mechanism
2009/04/07 09:26:28 42.342 13.388 10.0 4.70 Italy NO 20090407092628c Mechanism
2009/04/07 10:29:10 42.331 13.406 9.7 3.1 Italy NO 20090407102910 Mechanism
2009/04/07 12:29:28 42.437 13.403 12 3.30 Italy NO 20090407122928 Mechanism
2009/04/07 17:47:37 42.275 13.464 15.0 5.30 Italy NO 20090407174737c Mechanism
2009/04/07 21:34:29 42.380 13.376 10.0 4.20 Italy NO 20090407213429c Mechanism
2009/04/07 21:39:06 42.361 13.363 10.4 3.70 Italy NO 20090407213906 Mechanism
2009/04/07 22:29:50 42.284 13.489 9.6 3.1 Italy NO 20090407222950 Mechanism
2009/04/07 22:43:42 42.328 13.486 9.3 3.00 Italy NO 20090407224342 Mechanism
2009/04/08 03:00:34 42.299 13.459 10.0 3.50 Italy NO 20090408030034c Mechanism
2009/04/08 04:27:41 42.305 13.467 10.7 3.70 Italy NO 20090408042741c Mechanism
2009/04/08 10:34:09 42.352 13.381 9.2 3.10 Italy NO 20090408103409 Mechanism
2009/04/08 11:35:57 42.355 13.328 10.6 3.50 Italy NO 20090408113557c Mechanism
2009/04/08 13:02:28 42.502 13.367 9.7 3.1 Italy NO 20090408130228 Mechanism
2009/04/08 17:58:35 42.364 13.396 8.8 3.20 Italy NO 20090408175835 Mechanism
2009/04/08 21:11:04 42.297 13.570 10.1 3.10 Italy NO 20090408211104 Mechanism
2009/04/08 22:56:50 42.5070 13.3640 10.2 4.30 Italy NO 20090408225650c Mechanism
2009/04/08 23:18:06 42.391 13.325 10.8 3.30 Italy NO 20090408231806 Mechanism
2009/04/09 00:52:59 42.484 13.343 15.4 5.10 Italy NO 20090409005259c Mechanism
2009/04/09 02:37:26 42.498 13.335 10.4 3.10 Italy NO 20090409023726 Mechanism
2009/04/09 03:14:52 42.338 13.437 18.0 4.20 Italy NO 20090409031452c Mechanism
2009/04/09 03:41:55 42.510 13.332 9.8 3.10 Italy NO 20090409034155 Mechanism
2009/04/09 04:29:45 42.504 13.345 11.0 3.20 Italy NO 20090409042945 Mechanism
2009/04/09 04:32:44 42.445 13.420 8.1 4.00 Italy NO 20090409043244c Mechanism
2009/04/09 04:43:09 42.506 13.366 9.2 3.70 Italy NO 20090409044309c Mechanism
2009/04/09 06:10:29 42.491 13.397 9.4 3.10 Italy NO 20090409061029 Mechanism
2009/04/09 09:31:06 42.361 13.390 8.8 3.00 Italy NO 20090409093106 Mechanism
2009/04/09 13:00:29 42.299 13.467 9.9 3.00 Italy NO 20090409130029 Mechanism
2009/04/09 13:19:33 42.338 13.259 10.0 3.60 Italy NO 20090409131933c Mechanism
2009/04/09 15:18:14 42.308 13.495 10.0 3.20 Italy NO 20090409151814 Mechanism
2009/04/09 19:38:16 42.501 13.356 17.2 4.90 Italy NO 20090409193816c Mechanism
2009/04/09 20:47:01 42.493 13.305 10.0 3.10 Italy NO 20090409204701 Mechanism
2009/04/09 21:09:49 42.510 13.335 9.6 3.00 Italy NO 20090409210949 Mechanism
2009/04/09 22:40:06 42.481 13.298 10.9 3.60 Italy NO 20090409224006c Mechanism
2009/04/10 03:22:22 42.470 13.417 9.4 3.70 Italy NO 20090410032222c Mechanism
2009/04/10 04:33:04 42.458 13.350 10.5 3.30 Italy NO 20090410043304 Mechanism
2009/04/10 06:41:31 42.520 13.339 9.3 3.00 Italy NO 20090410064131 Mechanism
2009/04/10 11:53:09 42.243 13.484 9.6 3.10 Italy NO 20090410115309 Mechanism
2009/04/10 15:22:43 42.248 13.484 10.2 3.0 Italy NO 20090410152243 Mechanism
2009/04/10 19:07:21 42.375 13.393 9.5 3.10 Italy NO 20090410190721 Mechanism
2009/04/10 19:18:39 42.344 13.358 10.2 3.00 Italy NO 20090410191839 Mechanism
2009/04/11 05:39:00 42.386 13.402 10.7 3.30 Italy NO 20090411053900 Mechanism
2009/04/11 06:13:26 42.469 13.417 9.1 3.00 Italy NO 20090411061326 Mechanism
2009/04/11 06:57:02 42.387 13.406 10.5 3.20 Italy NO 20090411065702 Mechanism
2009/04/11 07:04:14 42.391 13.406 11.0 3.20 Italy NO 20090411070414 Mechanism
2009/04/11 15:42:29 42.523 13.316 8.7 3.10 Italy NO 20090411154229 Mechanism
2009/04/11 19:53:53 42.347 13.525 9.8 3.00 Italy NO 20090411195353 Mechanism
2009/04/12 03:29:35 42.536 13.316 9.7 3.00 Italy NO 20090412032935 Mechanism
2009/04/12 09:48:59 42.352 13.386 9.6 3.5 Italy NO 20090412094859 Mechanism
2009/04/12 18:05:16 42.395 13.394 9.8 3.40 Italy NO 20090412180516c Mechanism
2009/04/12 18:09:42 42.271 13.498 9.8 2.9 Italy NO 20090412180942 Mechanism
2009/04/13 07:08:30 42.268 13.484 9.3 3.10 Italy NO 20090413070830 Mechanism
2009/04/13 08:41:08 42.271 13.505 9.9 3.00 Italy NO 20090413084108 Mechanism
2009/04/13 13:36:04 42.444 13.440 9.0 3.40 Italy NO 20090413133604 Mechanism
2009/04/13 19:09:49 42.360 13.348 10.4 3.80 Italy NO 20090413190949c Mechanism
2009/04/13 19:17:57 42.360 13.354 11.3 3.50 Italy NO 20090413191757c Mechanism
2009/04/13 20:08:24 42.365 13.371 10.5 3.00 Italy NO 20090413200824 Mechanism
2009/04/13 21:14:24 42.504 13.363 7.5 4.90 Italy NO 20090413211424c Mechanism
2009/04/14 07:36:44 42.495 13.395 8.8 2.9 Italy NO 20090414073644 Mechanism
2009/04/14 09:08:07 42.256 13.489 10.6 3.2 Italy NO 20090414090807 Mechanism
2009/04/14 13:56:21 42.543 13.312 10.0 3.90 Italy NO 20090414135621c Mechanism
2009/04/14 17:27:30 42.527 13.295 3.6 3.50 Italy NO 20090414172730c Mechanism
2009/04/14 19:28:02 42.536 13.307 11.0 3.40 Italy NO 20090414192802c Mechanism
2009/04/14 20:17:27 42.530 13.288 10.4 4.10 Italy NO 20090414201727c Mechanism
2009/04/14 20:53:09 42.549 13.302 9.2 3.10 Italy NO 20090414205309 Mechanism
2009/04/15 11:44:40 42.287 13.474 10.7 3.00 Italy NO 20090415114440 Mechanism
2009/04/15 19:36:44 42.522 13.286 6.3 3.20 Italy NO 20090415193644 Mechanism
2009/04/15 19:55:57 42.466 13.365 9.3 3.00 Italy NO 20090415195557 Mechanism
2009/04/15 22:53:07 42.505 13.312 8.6 3.80 Italy NO 20090415225307c Mechanism
2009/04/16 05:44:54 42.289 13.404 9.9 3.20 Italy NO 20090416054454 Mechanism
2009/04/16 17:49:30 42.5400 13.2890 10.9 3.80 Italy NO 20090416174930c Mechanism
2009/04/18 09:05:56 42.441 13.361 14.6 3.80 Italy NO 20090418090556 Mechanism
2009/04/18 11:07:21 42.265 13.494 9.4 3.20 Italy NO 20090418110721 Mechanism
2009/04/18 13:03:08 42.332 13.500 10.2 3.1 Italy NO 20090418130308 Mechanism
2009/04/20 02:22:15 42.376 13.318 10.5 3.0 Italy NO 20090420022215 Mechanism
2009/04/20 07:13:14 42.407 13.349 10.1 3.1 Italy NO 20090420071314 Mechanism
2009/04/20 11:43:06 42.278 13.503 9.9 3.0 Italy NO 20090420114306 Mechanism
2009/04/21 15:44:36 42.330 13.366 10.7 3.60 Italy NO 20090421154436 Mechanism
2009/04/21 16:20:56 42.516 13.313 12.0 3.2 Italy NO 20090421162056 Mechanism
2009/04/23 15:14:08 42.247 13.492 9.9 4.0 Italy NO 20090423151408 Mechanism
2009/04/23 21:49:00 42.233 13.479 9.3 4.00 Italy NO 20090423214900 Mechanism
2009/04/24 04:36:17 42.263 13.466 10.3 3.00 Italy NO 20090424043617 Mechanism
2009/04/24 13:38:53 42.519 13.348 9.4 3.20 Italy NO 20090424133853 Mechanism
2009/04/24 14:24:07 42.386 13.394 8.3 3.00 Italy NO 20090424142407 Mechanism
2009/04/24 15:53:45 42.309 13.465 10.5 3.00 Italy NO 20090424155345 Mechanism
2009/04/24 22:51:29 42.267 13.508 11.0 3.0 Italy NO 20090424225129 Mechanism
2009/04/25 02:08:23 42.294 13.454 8.3 3.1 Italy NO 20090425020823 Mechanism
2009/04/25 11:13:04 42.416 13.334 9.1 3.00 Italy NO 20090425111304 Mechanism
2009/04/25 13:17:31 42.264 13.495 10.9 3.0 Italy NO 20090425131731 Mechanism
2009/04/26 17:56:06 42.456 13.378 10.6 3.30 Italy NO 20090426175606 Mechanism
2009/04/30 09:13:55 42.355 13.425 9.1 3.1 Italy NO 20090430091355 Mechanism
2009/04/30 13:01:01 42.361 13.364 10.90 3.50 Italy NO 20090430130101 Mechanism
2009/05/01 05:12:51 42.280 13.470 9.0 3.80 Italy NO 20090501051251 Mechanism
2009/05/02 20:15:00 42.291 13.492 8.8 3.2 Italy NO 20090502201500 Mechanism
2009/05/03 05:14:43 42.365 13.390 10.1 3.20 Italy NO 20090503051443 Mechanism
2009/05/05 10:44:03 42.282 13.498 10.3 3 Italy NO 20090505104403 Mechanism
2009/05/05 18:03:41 42.270 13.509 10.1 3.1 Italy NO 20090505180341 Mechanism
2009/05/08 01:02:47 42.268 13.583 7.90 3.20 Italy NO 20090508010247 Mechanism
2009/05/09 09:09:40 42.350 13.359 10.50 3.20 Italy NO 20090509090940 Mechanism
2009/05/10 16:00:07 42.301 13.479 10.0 3.50 Italy NO 20090510160007 Mechanism
2009/05/11 16:59:04 42.491 13.366 9.8 3.1 Italy NO 20090511165904 Mechanism
2009/05/14 06:30:22 42.501 13.406 7.9 3.80 Italy NO 20090514063022 Mechanism
2009/05/14 06:32:33 42.481 13.410 10.0 3.50 Italy NO 20090514063233 Mechanism
2009/05/14 20:30:54 42.368 13.318 10.2 3.30 Italy NO 20090514203054 Mechanism
2009/05/23 17:24:22 42.501 13.303 11.70 3.30 Italy NO 20090523172422 Mechanism
2009/05/25 16:37:28 42.256 13.568 7.8 3.20 Italy NO 20090525163728 Mechanism
2009/05/30 02:55:09 42.356 13.341 11.5 3.50 Italy NO 20090530025509 Mechanism
2009/05/31 09:09:49 42.271 13.554 9.9 3.0 Italy NO 20090531090949 Mechanism
2009/06/04 12:40:31 42.244 13.540 9.4 3.20 Italy NO 20090604124031 Mechanism
2009/06/07 19:21:34 42.350 13.483 10.4 3.60 Italy NO 20090607192134 Mechanism
2009/06/08 12:49:47 42.351 13.462 7.3 3.00 Italy NO 20090608124947 Mechanism
2009/06/11 07:04:49 42.335 13.438 10.6 3.40 Italy NO 20090611070449 Mechanism
2009/06/15 15:21:31 42.439 13.445 10.1 3.10 Italy NO 20090615152131 Mechanism
2009/06/16 18:52:57 42.297 13.391 12.3 3.10 Italy NO 20090616185257 Mechanism
2009/06/19 19:47:09 42.302 13.383 9.9 3.30 Italy NO 20090619194709 Mechanism
2009/06/20 05:41:15 42.332 13.377 10.7 3.10 Italy NO 20090620054115 Mechanism
2009/06/21 00:55:17 42.282 13.489 10.0 3.20 Italy NO 20090621005517 Mechanism
2009/06/21 16:31:11 42.567 13.195 9.9 3.40 Italy NO 20090621163111 Mechanism
2009/06/22 20:58:40 42.446 13.356 14.2 4.50 Italy NO 20090622205840 Mechanism
2009/06/22 22:49:20 42.441 13.333 13.8 3.1 Italy NO 20090622224920 Mechanism
2009/06/23 00:41:56 42.441 13.369 15.6 3.80 Italy NO 20090623004156 Mechanism
2009/06/23 08:35:08 42.462 13.347 10.7 3.50 Italy NO 20090623083508 Mechanism
2009/06/23 20:58:50 42.445 13.360 13.0 3.20 Italy NO 20090623205850 Mechanism
2009/06/25 16:14:57 42.569 13.193 9.9 3.30 Italy NO 20090625161457 Mechanism
2009/06/25 21:00:08 42.570 13.206 10.9 3.90 Italy NO 20090625210008 Mechanism
2009/06/26 07:14:30 42.567 13.189 9.9 3.40 Italy NO 20090626071430 Mechanism
2009/06/29 05:54:33 42.463 13.366 13.5 3.10 Italy NO 20090629055433 Mechanism
2009/06/30 00:38:10 42.569 13.198 10.5 3.40 Italy NO 20090630003810 Mechanism
2009/07/03 01:14:07 42.320 13.378 11.6 3.40 Italy NO 20090703011407 Mechanism
2009/07/03 09:43:53 42.328 13.361 10.1 3.60 Italy NO 20090703094353 Mechanism
2009/07/03 11:03:07 42.409 13.387 8.8 4.10 Italy NO 20090703110307 Mechanism
2009/07/03 23:12:55 42.276 13.403 7.7 3.20 Italy NO 20090703231255 Mechanism
2009/07/06 07:02:18 42.451 13.314 13.8 3.00 Italy NO 20090706070218 Mechanism
2009/07/12 08:38:51 42.338 13.378 10.8 4.00 Italy NO 20090712083851 Mechanism
2009/07/12 22:14:24 42.338 13.398 11.0 3.60 Italy NO 20090712221424 Mechanism
2009/07/15 00:58:06 42.466 13.284 10.0 3.00 Italy NO 20090715005806 Mechanism
2009/07/19 12:49:56 42.393 13.407 8.0 3.20 Italy NO 20090719124956 Mechanism
2009/07/23 22:37:32 42.251 13.500 9.4 3.00 Italy NO 20090723223732 Mechanism
2009/07/31 11:05:40 42.247 13.505 8.9 3.60 Italy NO 20090731110540 Mechanism
2009/08/02 22:39:28 42.365 13.391 10.3 3.10 Italy NO 20090802223928 Mechanism
2009/08/12 14:51:33 42.347 13.312 10.8 3.92 Italy NO 20090812145133 Mechanism
2009/08/20 03:44:07 42.234 13.523 9.7 3.12 Italy NO 20090820034407 Mechanism
2009/08/26 23:18:28 42.577 13.162 8.3 3.0 Italy NO 20090826231828 Mechanism
2009/08/31 14:09:10 42.246 13.515 9.5 3.1 Italy NO 20090831140910 Mechanism
2009/09/24 16:14:57 42.453 13.330 4.1 9.7 Italy NO 20090924161457 Mechanism
2009/10/20 05:07:30 42.398 13.24 9.9 3.5 Italy NO 20091020050730 Mechanism
2010/01/22 12:30:50 42.247 13.526 9.9 3.4 Italy NO 20100122123050 Mechanism
2010/08/31 03:00:11 42.543 13.196 3.0 3.4 Italy NO 20100831030011 Mechanism
2010/08/31 07:12:52 42.522 13.211 8.6 3.6 Italy NO 20100831071252 Mechanism
2010/08/31 12:06:25 42.543 13.201 2.3 3.3 Italy NO 20100831120625 Mechanism
2010/08/31 23:50:01 42.518 13.197 8.3 2.8 Italy NO 20100831235001 Mechanism
2010/09/03 02:24:25 42.516 13.223 10.0 3.3 Italy NO 20100903022425 Mechanism
2010/09/04 13:27:42 42.531 13.217 10.3 2.9 Italy NO 20100904132742 Mechanism
2010/12/06 10:32:15 42.795 13.012 8.9 3.40 Italy NO 20101206103215 Mechanism
2011/05/21 19:17:58 42.366 13.402 8.9 3.2 Italy NO 20110521191758 Mechanism

Other Earthquakes in Italy Inverted Using ISIDE waveforms using nnCIA model (PREFERRED)

DATE TIME LAT LON H ML LOCATION FELT DETAILS
2008/12/23 15:24:21 44.544 10.345 22.9 5.20 Italy NO 20081223152421 Mechanism
2008/12/23 21:58:26 44.527 10.355 23.7 4.80 Italy NO 20081223215826 Mechanism
2008/12/25 03:08:29 44.556 10.309 21.9 3.90 Italy NO 20081225030829 Mechanism
2009/04/19 12:39:50 44.727 7.845 40.2 3.90 Italy NO 20090419123950 Mechanism
2009/04/22 12:32:25 42.578 12.827 9.2 3.60 Italy NO 20090422123225 Mechanism
2009/03/17 01:12:50 41.986 14.017 6.7 3.6 Italy NO 20090317011250 Mechanism
2009/03/29 08:43:07 41.985 14.002 8.1 3.8 Italy NO 20090329084307 Mechanism
2009/06/25 23:31:54 43.256 13.085 7.6 3.20 Italy NO 20090625233154 Mechanism
2009/06/28 17:57:27 44.300 9.949 5.4 3.30 Italy NO 20090628175727 Mechanism
2009/08/04 16:22:18 41.738 14.224 20.2 3.10 Italy NO 20090804162218 Mechanism
2009/08/04 21:42:54 41.731 14.238 19.7 3.10 Italy NO 20090804214254 Mechanism
2009/08/06 15:36:44 41.632 13.666 11.1 3.90 Italy NO 20090806153644 Mechanism
2009/08/16 07:11:26 42.483 12.705 7.6 3.12 Italy NO 20090816071126 Mechanism
2009/09/11 06:34:37 46.545 9.692 7.2 3.2 Italy NO 20090911063437 Mechanism
2009/09/14 20:04:31 44.012 11.284 3.5 4.2 Italy NO 20090914200431 Mechanism
2009/09/21 22:01:27 42.739 12.491 2.0 3.2 Italy NO 20090921220127 Mechanism
2009/09/30 19:52:12 41.725 13.691 3.5 12 Italy NO 20090930195212 Mechanism
2009/10/19 10:08:50 44.76 9.735 25.8 3.9 Italy NO 20091019100850 Mechanism
2010/01/31 21:21:30 42.273 13.413 10.2 3.2 Italy NO 20100131212130 Mechanism
2010/02/01 01:42:00 40.628 15.706 9.4 3.2 Italy NO 20100201014200 Mechanism
2010/02/02 19:42:43 43.101 13.389 9.7 3.5 Italy NO 20100202194243 Mechanism
2010/02/03 11:16:45 43.129 13.431 22.0 3.2 Italy NO 20100203111645 Mechanism
2010/04/15 01:47:36 43.477 12.425 9.1 3.7 Italy NO 20100415014736 Mechanism
2010/05/04 12:26:51 44.166 11.526 9.4 3.1 Italy NO 20100504122651 Mechanism
2010/05/15 05:09:43 46.125 7.730 10.1 3.1 Italy NO 20100515050943 Mechanism
2010/06/16 22:39:41 38.832 16.146 8.6 3.7 Italy NO 20100616223941 Mechanism
2010/07/04 11:38:58 42.159 13.393 7.5 3.6 Italy NO 20100704113858 Mechanism
2010/07/04 16:34:54 43.753 8.182 13.3 3.6 Italy NO 20100704163454 Mechanism
2010/07/13 03:36:18 40.581 15.452 10.4 3.4 Italy NO 20100713033618 Mechanism
2010/09/01 13:11:32 42.840 12.671 2.4 2.9 Italy NO 20100901131132 Mechanism
2010/08/11 21:40:44 43.657 12.001 8.0 3.0 Italy NO 20100811214044 Mechanism
2010/08/18 14:17:08 41.650 14.274 14.0 3.0 Italy NO 20100818141708 Mechanism
2010/08/28 07:08:03 42.845 12.661 8.0 4.0 Italy NO 20100828070803 Mechanism
2010/09/17 12:20:18 41.4900 15.6300 30.1 4.40 Italy NO 20100917122018 Mechanism
2010/08/29 10:11:17 42.837 12.664 5.7 3.1 Italy NO 20100829101117 Mechanism
2010/09/01 13:11:32 42.840 12.671 2.4 2.9 Italy NO 20100901131132 Mechanism
2010/09/05 07:07:23 44.107 12.170 30.0 3.7 Italy NO 20100905070723 Mechanism
2010/09/16 06:20:32 44.375 11.006 28.2 3.1 Italy NO 20100916062032 Mechanism
2010/09/17 12:20:18 41.4900 15.6300 30.1 4.40 Italy NO 20100917122018 Mechanism
2010/09/19 00:00:58 44.186 11.563 5.0 3.50 Italy NO 20100919000058 Mechanism
2010/10/13 22:43:14 44.141 12.369 35.2 4.10 Italy NO 20101013224314 Mechanism
2010/11/09 08:43:19 40.039 15.929 11.5 3.60 Italy NO 20101109084319 Mechanism
2011/01/09 10:58:20 42.108 13.334 8.1 3.9 Italy NO 20110109105820 Mechanism
2011/04/04 13:11:51 41.675 14.918 19.5 3.3 Italy NO 20110404131151 Mechanism
2011/04/12 03:32:55 41.663 16.117 10.0 3.90 Italy NO 20110412033255 Mechanism
2011/05/06 15:12:35 37.782 14.960 22.2 4.0 Italy NO 20110506151235 Mechanism
2011/05/24 22:03:55 43.860 12.030 5.0 3.7 Italy NO 20110524220355 Mechanism
2011/05/25 00:05:41 43.896 12.019 7.5 3.1 Italy NO 20110525000541 Mechanism
2011/05/25 00:07:58 43.881 12.015 7.4 3.1 Italy NO 20110525000758 Mechanism
2011/05/25 04:07:46 43.841 12.007 5.1 3.2 Italy NO 20110525040746 Mechanism
2011/06/04 16:12:00 43.763 11.932 9.9 3.4 Italy NO 20110604161200 Mechanism
2011/06/04 18:06:50 43.893 11.979 9.2 3.3 Italy NO 20110604180650 Mechanism
2011/06/04 22:18:37 43.862 11.984 7.3 3.3 Italy NO 20110604221837 Mechanism
2011/06/17 11:33:10 43.128 12.564 9. 3.2 Italy NO 20110617113310 Mechanism
2011/06/19 14:35:34 44.09 10.76 15. 3.6 Italy NO 20110619143534 Mechanism

Preferred Source Parameter Summary

The source parameters contained in the links above for the preferred solutions are given in the following table. The origin time and source coordinates are taken from the ISIDE listing. The depth, moment magnitude and strike, dip and rake of one of the nodal planes are from the grid search inversion. The FIT parameter is a number such that 1.0 is a perfect fit; the larger number is better. The FIT parameter depends upon data quality and the velocity model used. 

   DATE   TIME    LAT      LON     H   Mw  STK DIP RAKE  FIT 
20081001_224737  42.590   13.287 15.0 3.20 320  75  -90 0.5305
20090330_133838  42.326   13.362 10.0 4.08  10  45  -35 0.5311
20090330_134326  42.303   13.364 10.0 3.53 340  35  -80 0.5226
20090330_190528  42.316   13.373 11.0 3.29 185  50  -25 0.5953
20090330_215717  42.316   13.375 11.0 3.46 335  35  -85 0.5977
20090403_044442  42.327   13.358 11.0 3.15 180  50  -45 0.7214
20090405_204854  42.332   13.372 10.0 3.92  10  45  -35 0.5277
20090405_223941  42.341   13.380  9.0 3.47  20  60  -30 0.4634
20090406_013239  42.334   13.334  5.0 6.13 135  55  -95 0.6980
20090406_022746  42.374   13.342 11.0 4.10 175  65  -75 0.3530
20090406_023704  42.366   13.340 10.0 4.81   0  35  -50 0.5449
20090406_035645  42.336   13.387  7.0 4.26 145  60  -95 0.4399
20090406_040845  42.376   13.356  7.0 3.33  20  40  -35 0.4067
20090406_044753  42.352   13.347  9.0 3.82 350  30  -50 0.4978
20090406_062105  42.317   13.416 12.0 3.54 320  30  -80 0.5924
20090406_064815  42.303   13.383  5.0 3.25 200  85  -35 0.4598
20090406_071710  42.355   13.367  6.0 4.03 335  35  -75 0.3428
20090406_072845  42.347   13.390  7.0 3.37  35  55  -15 0.5967
20090406_073941  42.324   13.371  7.0 3.47 160  50  -90 0.4929
20090406_084013  42.364   13.366  7.0 3.37   5  45  -50 0.5584
20090406_093012  42.373   13.341  9.0 3.27   5  50  -40 0.4640
20090406_094702  42.264   13.393  4.0 3.19 235  25   30 0.5200
20090406_095929  42.322   13.381  9.0 3.32 205  65   -5 0.5656
20090406_103618  42.343   13.402  6.0 3.31  15  50  -35 0.4716
20090406_125516  42.372   13.353  6.0 3.40 345  60  -80 0.4786
20090406_141438  42.365   13.338  9.0 3.52 350  45  -60 0.4904
20090406_160618  42.234   13.483  8.0 3.08 160  70  -80 0.6084
20090406_163809  42.362   13.333  9.0 4.30   0  40  -55 0.5565
20090406_165726  42.346   13.307  7.0 3.30   5  50  -35 0.5836
20090406_174004  42.376   13.334  7.0 3.37 345  30  -65 0.6230
20090406_200334  42.213   13.479  7.0 3.30 350  35  -60 0.6002
20090406_215653  42.396   13.323  5.0 3.79 175  55  -55 0.6509
20090406_224713  42.349   13.293 10.0 3.60 335  40  -55 0.5149
20090406_231537  42.451   13.364  7.0 4.90 330  40  -90 0.5269
20090406_234934  42.349   13.378  5.0 3.20 155  50  -60 0.4707
20090407_015203  42.432   13.393  8.0 3.30 340  40  -85 0.5101
20090407_092628  42.342   13.388  9.0 4.75 355  30  -65 0.3892
20090407_102910  42.331   13.406  7.0 3.14 160  60  -75 0.5990
20090407_122928  42.437   13.403  7.0 3.59 335  35  -85 0.6330
20090407_174737  42.275   13.464 16.0 5.42 340  70  -60 0.6708
20090407_213429  42.380   13.376  5.0 4.22 330  45  -70 0.5867
20090407_213906  42.361   13.363  8.0 3.61   0  45  -55 0.6314
20090407_222950  42.284   13.489  7.0 3.29  50  25  -35 0.4974
20090407_224342  42.328   13.486  0.5 2.99 140  40  -90 0.5343
20090408_030034  42.299   13.459  7.0 3.76   0  25  -50 0.3667
20090408_042741  42.305   13.467  7.0 3.92   5  25  -45 0.3859
20090408_103409  42.352   13.381  5.0 3.47 340  40  -80 0.3412
20090408_113557  42.355   13.328  7.0 3.35  15  55  -15 0.5077
20090408_130228  42.502   13.367  6.0 3.03 315  25  -90 0.5149
20090408_175835  42.364   13.396  2.0 3.32 335  55  -75 0.5485
20090408_211104  42.297   13.570  0.5 3.02 155  50  -75 0.4859
20090408_225650  42.507   13.364  7.0 3.86 325  45  -70 0.5817
20090408_231806  42.391   13.325  6.0 3.50 350  40  -60 0.6084
20090409_005259  42.484   13.343  7.0 5.22 325  50  -90 0.5524
20090409_023726  42.498   13.335  7.0 3.19 125  25  -95 0.6060
20090409_031452  42.338   13.437 12.0 4.20 150  90   55 0.5897
20090409_034155  42.510   13.332  7.0 3.20 335  40  -80 0.5278
20090409_042945  42.504   13.345  7.0 3.11 330  55  -70 0.5558
20090409_043244  42.445   13.420  7.0 4.11   5  55  -45 0.4437
20090409_044309  42.506   13.366  7.0 3.69 325  35  -80 0.5508
20090409_061029  42.491   13.397  5.0 3.04 200  65  -55 0.4657
20090409_093106  42.361   13.390  5.0 3.22 340  30  -75 0.4558
20090409_130029  42.299   13.467  6.0 3.23  45  50  -10 0.3626
20090409_131933  42.338   13.259  9.0 3.79 330  50  -65 0.4720
20090409_151814  42.308   13.495  5.0 3.36 350  30  -50 0.3181
20090409_193816  42.501   13.356  7.0 4.98 135  45  -95 0.3778
20090409_204701  42.493   13.305  7.0 3.12 320  60  -75 0.5349
20090409_210949  42.510   13.335  6.0 3.08 345  45  -60 0.5291
20090409_224006  42.481   13.298 10.0 3.71 315  85  -80 0.6534
20090410_032222  42.470   13.417  5.0 3.74 305  45  -95 0.4736
20090410_043304  42.458   13.350 10.0 3.34 180  15  -35 0.6175
20090410_064131  42.520   13.339  6.0 3.07 330  35  -75 0.5516
20090410_115309  42.243   13.484  7.0 3.32 340  30  -50 0.4769
20090410_152243  42.248   13.484  7.0 3.29   0  35  -20 0.4756
20090410_190721  42.375   13.393  2.0 3.14 130  40 -100 0.3181
20090410_191839  42.344   13.358  9.0 3.10 340  40  -55 0.4396
20090411_053900  42.386   13.402  7.0 3.44 330  40  -75 0.5915
20090411_061326  42.469   13.417  5.0 3.19 145  55  -90 0.5347
20090411_065702  42.387   13.406  8.0 3.26 135  45  -95 0.5660
20090411_070414  42.391   13.406  8.0 3.31 325  40  -80 0.5114
20090411_154229  42.523   13.316  7.0 3.21 340  35  -70 0.4815
20090411_195353  42.347   13.525  0.5 3.04 315  45  -95 0.5073
20090412_032935  42.536   13.316  7.0 3.16 340  40  -75 0.4777
20090412_094859  42.352   13.386  6.0 3.40  15  50  -40 0.5528
20090412_180516  42.395   13.394  2.0 3.21 135  50  -85 0.4748
20090412_180942  42.271   13.498  6.0 2.92 160  70  -80 0.3495
20090413_070830  42.268   13.484  7.0 3.23 140  55  -75 0.5111
20090413_084108  42.271   13.505  7.0 3.17 170  65  -35 0.6010
20090413_133604  42.444   13.440  7.0 3.65  15  60  -30 0.5765
20090413_190949  42.360   13.348  9.0 3.73  10  40  -50 0.4873
20090413_191757  42.360   13.354  9.0 3.55  10  35  -35 0.4918
20090413_200824  42.365   13.371  6.0 3.01 350  35  -50 0.3477
20090413_211424  42.504   13.363  6.0 4.85 335  30  -80 0.5805
20090414_073644  42.495   13.395  6.0 3.00 345  40  -40 0.6260
20090414_090807  42.256   13.489  8.0 3.16  -5  25  -50 0.5498
20090414_135621  42.543   13.312  6.0 3.84 155  50  -90 0.4430
20090414_172730  42.527   13.295  6.0 3.75 330  40  -80 0.5475
20090414_192802  42.536   13.307  7.0 3.35 345  50  -70 0.5098
20090414_201727  42.530   13.288  7.0 3.79 330  45  -90 0.6535
20090414_205309  42.549   13.302  6.0 3.28 330  45  -90 0.5870
20090415_114440  42.287   13.474  7.0 3.30  15  25  -40 0.5078
20090415_193644  42.522   13.286  5.0 3.41 155  20  -65 0.5739
20090415_195557  42.466   13.365  8.0 3.04 195  40  -20 0.4579
20090415_225307  42.505   13.312  6.0 3.86 330  40  -80 0.5594
20090416_054454  42.289   13.404  8.0 3.39 350  40  -60 0.4987
20090416_174930  42.540   13.289  7.0 3.76 165  30  -70 0.5234
20090418_090556  42.441   13.361 10.0 3.71 175  30  -45 0.6071
20090418_110721  42.265   13.494  6.0 3.53 150  65  -75 0.5298
20090418_130308  42.332   13.500  1.0 2.81 305  50  -95 0.4308
20090420_022215  42.376   13.318  9.0 3.01  -5  40  -75 0.5230
20090420_071314  42.407   13.349  7.0 3.05  -5  65  -65 0.6194
20090420_114306  42.278   13.503  7.0 3.03 170  70  -35 0.6304
20090421_154436  42.330   13.366 10.0 3.53   0  40  -60 0.5899
20090421_162056  42.512   13.313  8.0 2.98 150  20  -75 0.5442
20090423_151408  42.247   13.492  7.0 3.84 345  30  -50 0.5456
20090423_214900  42.233   13.479  7.0 4.06 345  35  -65 0.6110
20090424_043617  42.263   13.466  7.0 3.26   0  20  -45 0.5244
20090424_133853  42.519   13.348  5.0 3.23 350  45  -60 0.5640
20090424_142407  42.386   13.394  1.0 3.04 145  40  -75 0.4203
20090424_155345  42.309   13.465  6.0 3.19 350  25  -55 0.4374
20090424_225129  42.267   13.508  7.0 3.14 165  65  -40 0.7459
20090425_020823  42.294   13.454  6.0 3.22   5  25  -45 0.4983
20090425_111304  42.416   13.334  8.0 3.07   5  70  -25 0.5116
20090425_131731  42.264   13.495 10.0 3.13 145  50  -75 0.6692
20090426_175606  42.456   13.378  8.0 2.93 325  40  -60 0.4796
20090430_091355  42.355   13.425  2.0 2.93 165  45  -60 0.3914
20090430_130101  42.361   13.364  7.0 3.52   5  40  -40 0.6103
20090501_051251  42.280   13.470  7.0 3.69   5  15  -45 0.5349
20090502_201500  42.263   13.495  1.0 3.12  35  75   15 0.5585
20090503_051443  42.365   13.390  5.0 3.27 345  35  -70 0.4128
20090505_104403  42.282   13.498  4.0 3.10  45  35  -10 0.5334
20090505_180341  42.270   13.509  7.0 3.28 330  30  -95 0.5094
20090508_010247  42.268   13.583  1.0 3.18  30  55  -70 0.4655
20090509_090940  42.350   13.359  9.0 3.37 340  35  -70 0.5286
20090510_160007  42.301   13.479  1.0 3.25 345  45  -75 0.4979
20090511_165904  42.491   13.366  7.0 3.25 170  30  -60 0.5938
20090514_063022  42.501   13.406  6.0 3.50 155  55  -85 0.5491
20090514_063233  42.481   13.410  6.0 3.43 325  35  -95 0.5324
20090514_203054  42.368   13.318 10.0 3.35 140  80  -75 0.6093
20090523_172422  42.501   13.303  6.0 3.04 315  65  -90 0.5467
20090525_163728  42.256   13.568  1.0 3.18 340  50  -75 0.4269
20090530_025509  42.356   13.341  9.0 3.57   5  40  -50 0.5452
20090531_090949  42.271   13.554  1.0 2.94 145  40  -90 0.5124
20090604_124031  42.244   13.540  5.0 3.20 310  25 -100 0.4306
20090607_192134  42.350   13.483  1.0 3.29 315  50  -70 0.4965
20090608_124947  42.351   13.462  1.0 2.85 300  50  -85 0.5271
20090611_070449  42.335   13.438  6.0 3.30 330  20  -65 0.5502
20090615_152131  42.439   13.445  5.0 2.98 145  20 -100 0.4770
20090616_185257  42.297   13.391 12.0 3.06   0  40  -45 0.4770
20090619_194709  42.302   13.383 10.0 3.15 160  40  -80 0.6193
20090620_054115  42.332   13.377  9.0 3.03 -10  35  -70 0.5362
20090621_005517  42.282   13.489  8.0 3.14  20  30  -60 0.4126
20090621_163111  42.567   13.195  3.0 3.19 325  40  -80 0.4976
20090622_205840  42.446   13.356 10.0 4.39 320  90  -75 0.7370
20090622_224920  42.441   13.333 10.0 2.90 140  85   65 0.6804
20090623_004156  42.441   13.369 10.0 3.75 190  15  -30 0.6833
20090623_083508  42.462   13.347  9.0 3.43 320  85  -70 0.5157
20090623_205850  42.445   13.360 10.0 3.12 180  20  -45 0.5661
20090625_161457  42.569   13.193  4.0 3.03 315  30  -90 0.5271
20090625_210008  42.570   13.206  5.0 3.55 145  50  -80 0.5741
20090626_071430  42.567   13.189  5.0 3.44 340  40  -75 0.5376
20090629_055433  42.463   13.366 10.0 3.21 335  65  -60 0.5393
20090630_003810  42.569   13.198  4.0 3.44 135  50  -95 0.5275
20090703_011407  42.320   13.378  8.0 3.48 355  40  -70 0.5255
20090703_094353  42.328   13.361 10.0 3.43 350  40  -65 0.4932
20090703_110307  42.409   13.387  2.0 3.68 310  55  -70 0.4425
20090703_231255  42.276   13.403  2.0 3.15 165  40  -45 0.3607
20090706_070218  42.451   13.314 10.0 3.02 145  80   50 0.6042
20090712_083851  42.338   13.378  9.0 4.09 350  40  -65 0.6181
20090712_221424  42.338   13.398  9.0 3.70 335  35  -70 0.6161
20090715_005806  42.466   13.284  4.0 2.75 125  60  -65 0.4080
20090719_124956  42.393   13.407  0.5 3.19 350  55  -80 0.5665
20090723_223732  42.251   13.500  9.0 3.27 145  60  -60 0.6291
20090731_110540  42.247   13.505  6.0 3.92 145  65  -95 0.5446
20090802_223928  42.365   13.391  5.0 3.28 340  40  -70 0.5700
20090812_145133  42.347   13.312  7.0 3.34 185  20  -35 0.7149
20090820_034407  42.234   13.523  7.0 3.35  15  35  -35 0.4679
20090826_231828  42.577   13.162  3.0 3.03 320  50  -90 0.5589
20090831_140910  42.246   13.515  7.0 3.29  25  20  -25 0.5210
20090924_161457  42.453   13.330 13.0 3.77 185  45  -75 0.5857
20091020_050730  42.398   13.240  2.0 3.55  10  70  -60 0.5417
20100122_123050  42.247   13.526  5.0 3.47   5  30  -45 0.4919
20100831_030011  42.543   13.196  4.0 3.32 320  50  -60 0.5241
20100831_071252  42.522   13.211  5.0 3.55 310  50  -60 0.4675
20100831_120624  42.543   13.201  5.0 3.31 300  30  -85 0.5057
20100831_235001  42.518   13.197  5.0 3.01 290  35  -60 0.5739
20100903_022425  42.516   13.223  5.0 3.29 310  45  -45 0.5911
20100904_132742  42.531   13.217  4.0 2.93 350  55  -40 0.4492
20101206_103215  42.795   13.012  6.0 3.38 160  45  -65 0.5036
20110521_191758  42.366   13.402  2.0 3.09 335  40  -75 0.5260
20081223_152421  44.544   10.345 22.0 5.21  95  55   80 0.7429
20081223_215826  44.527   10.355 22.0 4.61  95  50   85 0.5410
20081225_030829  44.556   10.309 19.0 3.88 115  60   80 0.3617
20090419_123950  44.727    7.845 33.0 3.69 165  80  -30 0.5201
20090422_123225  42.578   12.827  3.0 3.31   5  45  -80 0.4792
20090317_011250  41.986   14.017  6.0 3.66 315  75  -75 0.4753
20090329_084307  41.985   14.002  6.0 3.84 320  90  -90 0.5796
20090625_233154  43.256   13.085  6.0 3.13 175  55  -65 0.4202
20090628_175727  44.300    9.949  6.0 3.23 335  60  -65 0.5515
20090804_162218  41.738   14.224 17.0 3.20  25  80  -20 0.4549
20090804_214254  41.731   14.238 15.0 3.28  30  80  -25 0.5352
20090806_153644  41.632   13.666 13.0 4.06 350  65  -50 0.5261
20090816_071126  42.483   12.705  6.0 3.10  20  35  -65 0.4482
20090911_063437  46.545    9.692 11.0 3.04 345  55  -45 0.5770
20090914_200431  44.012   11.284  6.0 4.12 145  50  -65 0.5284
20090921_220127  42.739   12.491  2.0 3.08 145  45  -85 0.4523
20090930_195212  41.725   13.691  9.0 3.34   5  70  -35 0.4163
20091019_100850  44.760    9.735 23.0 3.76  20  45   45 0.4862
20100131_212130  42.273   13.413 12.0 3.29   5  55  -35 0.4938
20100201_014200  40.628   15.706 10.0 3.38 220  75  -70 0.4510
20100202_194243  43.101   13.389 19.0 3.40 270  75   60 0.5618
20100203_111645  43.129   13.431 14.0 3.20 250  60  -20 0.5096
20100415_014736  43.477   12.425  5.0 3.74 315  60  -95 0.5756
20100504_122651  44.166   11.526 19.0 3.27 100  60   75 0.4818
20100515_050943  46.125    7.730 10.0 3.04 340  40  -20 0.3968
20100616_223941  38.832   16.146 10.0 3.82 115  55  -10 0.6030
20100704_113858  42.159   13.393  1.0 3.62 315  45  -85 0.6272
20100704_163454  43.753    8.182  5.0 3.43  15  85    5 0.7234
20100713_033618  40.581   15.452  7.0 3.56 165  20  -85 0.5947
20100901_131132  42.840   12.671  6.0 3.25   5  80  -95 0.5752
20100811_214044  43.657   12.001  5.0 3.31 315  35  -80 0.4476
20100818_141708  41.650   14.274 10.0 3.20 330  35  -50 0.4730
20100828_070803  42.845   12.661  6.0 4.08 340  75  -90 0.6239
20100917_122018  41.490   15.630 24.0 4.08 165  40   -5 0.5162
20100829_101117  42.837   12.664  6.0 3.34 190  10  -75 0.5781
20100901_131132  42.840   12.671  6.0 3.25   5  80  -95 0.5752
20100905_070723  44.107   12.170 17.0 3.73 115  30   70 0.5105
20100916_062032  44.375   11.006 21.0 3.32  85  65   65 0.4712
20100917_122018  41.490   15.630 24.0 4.08 165  40   -5 0.5162
20100919_000058  44.186   11.563 17.0 3.44 260  60  -20 0.6039
20101013_224313  44.141   12.369 22.0 3.82  20  40   25 0.6034
20101109_084319  40.039   15.929  8.0 3.58 330  50  -70 0.4968
20110109_105820  42.108   13.334  3.0 3.56 140  45  -65 0.3790
20110404_131151  41.675   14.918 14.0 3.35 170  70  -20 0.4421
20110412_033255  41.663   16.117  9.0 3.61 200  50   55 0.5627
20110506_151235  37.782   14.960 23.0 4.07  10  45   15 0.4206
20110524_220355  43.860   12.030  5.0 4.00 140  60  -65 0.4364
20110525_000541  43.896   12.019  6.0 3.36 300  30  -80 0.4304
20110525_000757  43.881   12.015  5.0 3.27 340  45  -20 0.3464
20110525_040746  43.841   12.007  8.0 3.54  35  40   90 0.5024
20110604_161200  43.763   11.932  9.0 3.55 325  80   -5 0.6760
20110604_180650  43.893   11.979  6.0 3.73 105  60  -80 0.5008
20110604_221837  43.862   11.984  9.0 3.44 335  80    5 0.5507
20110617_113310  43.128   12.564  7.0 3.22  45  15  -10 0.5962
20110619_143533  44.090   10.760  8.0 3.72 305  25  -70 0.5814

Inversion using European Regional Broadband Waveforms

2009/04/06 01:32:44 42.480 13.160 32.0 6.70 ITALY y 20090406013244 Mechanism
2009/04/06 23:15:37 42.4670 13.3900 2.0 4.90 ITALY y 20090406231537 Mechanism
2009/04/07 17:47:38 42.3490 13.4050 10.0 5.50 CENTRAL ITALY NO 20090407174738 Mechanism
2009/04/09 00:52:59 42.4800 13.3400 5.0 5.20 CENTRAL ITALY y 20090409005259 Mechanism
2009/04/09 19:38:18 42.5420 13.3030 10.0 5.00 CENTRAL ITALY y 20090409193818 Mechanism

Initial Inversion using ISIDE waveforms using WUS model
DATE TIME LAT LON H ML LOCATION FELT DETAILS
2009/04/06 02:37:04 42.366 13.340 10.1 4.60 Italy NO 20090406023704 Mechanism
2009/04/06 03:56:45 42.336 13.387 10. 3.90 Italy NO 20090406035645 Mechanism
2009/04/06 04:47:53 42.352 13.347 9.4 3.70 Italy NO 20090406044753 Mechanism
2009/04/06 16:38:09 42.362 13.333 10.0 4.00 Italy NO 20090406163809 Mechanism
2009/04/06 21:56:53 42.396 13.323 9.7 3.80 Italy NO 20090406215653 Mechanism
2009/04/06 23:15:37 42.4510 13.3640 8.0 4.80 Italy NO 20090406231537 Mechanism
2009/04/07 09:26:28 42.342 13.388 10.0 4.70 Italy NO 20090407092628 Mechanism
2009/04/07 17:47:37 42.275 13.464 15.0 5.30 Italy NO 20090407174737 Mechanism
2009/04/07 21:34:29 42.380 13.376 10.0 4.20 Italy NO 20090407213429 Mechanism
2009/04/08 22:56:50 42.5070 13.3640 10.2 4.30 Italy NO 20090408225650 Mechanism
2009/04/09 00:52:59 42.484 13.343 15.4 5.10 Italy NO 20090409005259 Mechanism
2009/04/09 03:14:52 42.338 13.437 18.0 4.20 Italy NO 20090409031452 Mechanism
2009/04/09 04:32:44 42.445 13.420 8.1 4.00 Italy NO 20090409043244 Mechanism
2009/04/09 19:38:16 42.501 13.356 17.2 4.90 Italy NO 20090409193816 Mechanism
2009/04/10 03:22:22 42.470 13.417 9.4 3.70 Italy NO 20090410032222 Mechanism
2009/04/13 21:14:24 42.504 13.363 7.5 4.90 Italy NO 20090413211424 Mechanism
2009/04/14 20:17:27 42.530 13.288 10.4 4.10 Italy NO 20090414201727 Mechanism
2009/04/15 22:53:07 42.505 13.312 8.6 3.80 Italy NO 20090415225307 Mechanism

Comparison of Fits with WUS, CIA(a), nCIA(b) and nnCIA(c) models

Recognizing that the WUS model is not the proper model for this region of Italy, an initial attempt at defining the upper crust S-wave velocity in the source region was made by determining fundamental mode Love and Rayleigh group velocitiesto INGV stations from the aftershocks. The program do_mft was used to extract the group velocities. This is not simple over paths up to 200 km because of the filtering effect of source depth and mechanism. The dispersion measurements from one earthquake were used to modify a crustal reflection model by using the program surf96. Three models were created: CIA.mod, which departed a lot from the initial model, and nCIA.mod which only permitted the upper 10 km of the starting model to change. Finally the nnCIA.mod was created by permitting larger variations from the starting model and by using more dispersion measurements.

Green's functions were computed to source depths of 29 km for each of the 3 models. These were each used in the source inversion. For an earthquake, the FIT value with the larges value, is a vote in favor of that model.

Another way to evaluate a model is to compare the observed group velocity dispersion to the model predictions:

In this figure the colored curves indicate the crustal model (WUS - black ; CIA - red ; nCIA - blue) and the black dots are are dispersion measurements. With further measurements, it may be possible to create another model.
The models considered are shown in the next figure:

Comparison of velocity models: WUS.mod (red), CIA.mod (yellow), nCIA.mod (green), nnCIA.mod (green-blue). The starting model for the CIA models is CIAo.mod (blue). The starting model was based on the model at stations 7-8 (Figure 5) in the study by Di Luzio et al (2009). [ Di Luzio, E., G. Mele, M. M. Tiberti, G. P. Cavinato and M. Parotto (2009). Moho deepening ans shallow crustal delamination beneath the central Apennines, Earth and Planetary Science Letters 280, 1-12.].

In performing the inversion of the group velocity dispersion, weighting was assigned to focus the inversion onto the shallow structure. The nnCIA.mod calls for a low velocity zone nearer to the surface than in the deep seismic-sounding model of Di Luzio et al. This velocity inversion seems necessary to fit the Rayleigh group velocity monimum at 20 seconds. It may be coincidental that the inversion starts at about 8km from the surface, which is almost the depth of many of the aftershocks. Is there a relatiion between the velocity model and depth of nucleation of the earthquakes?

The waveform fits prefer the CIA.mod althrough the observed dispersion is not fit well by this model. The nCIA.mod provides better fits than the WUS.mod but with about the same Mw. The reason that the CIA.mod Mw's and depths are lower is because the CIA.mod has a lover velocity upper crust.

10.0 205 30 -20 4.85 0.4712 20090406023704
10.0 0 40 -45 4.77 0.5067 20090406023704a
12.0 0 35 -50 4.89 0.4998 20090406023704b
10.0 0 35 -50 4.81 0.5449 20090406023704c
10.0 190 35 -40 4.28 0.3876 20090406035645
8.0 350 40 -60 4.16 0.3930 20090406035645a
10.0 185 35 -45 4.26 0.3957 20090406035645b
7.0 145 60 -95 4.26 0.4399 20090406035645c
8.0 270 15 50 3.88 0.5267 20090406044753
7.0 290 15 70 3.74 0.5465 20090406044753a
8.0 265 15 45 3.84 0.5297 20090406044753b
9.0 350 30 -50 3.82 0.4978 20090406044753c
11.0 190 40 -45 4.40 0.5073 20090406163809
9.0 350 40 -70 4.27 0.5277 20090406163809a
11.0 175 40 -65 4.39 0.5097 20090406163809b
9.0 0 40 -55 4.30 0.5565 20090406163809c
8.0 10 75 -25 3.79 0.5144 20090406215653
5.0 185 65 -40 3.69 0.5947 20090406215653a
6.0 190 70 -25 3.70 0.5427 20090406215653b
5.0 175 55 -55 3.79 0.6509 20090406215653c
9.0 160 40 -80 4.94 0.4330 20090406231537
7.0 155 45 -85 4.81 0.4758 20090406231537a
9.0 155 45 -85 4.93 0.4568 20090406231537b
7.0 330 40 -90 4.90 0.5269 20090406231537c
12.0 0 30 -60 4.87 0.3661 20090407092628
9.0 350 30 -70 4.72 0.3739 20090407092628a
11.0 -5 30 -65 4.84 0.3877 20090407092628b
9.0 355 30 -65 4.75 0.3892 20090407092628c
18.0 340 75 -60 5.50 0.6232 20090407174737
17.0 335 70 -70 5.43 0.6074 20090407174737a
17.0 340 70 -60 5.45 0.6372 20090407174737b
16.0 340 70 -60 5.42 0.6708 20090407174737c
5.0 165 60 -40 4.14 0.4730 20090407213429
4.0 330 50 -65 4.13 0.5183 20090407213429a
5.0 165 60 -35 4.12 0.5010 20090407213429b
5.0 330 45 -70 4.22 0.5867 20090407213429c
8.0 160 25 -50 3.86 0.5144 20090408225650
7.0 320 60 -80 3.75 0.5113 20090408225650a
8.0 155 25 -60 3.84 0.5270 20090408225650b
7.0 325 45 -70 3.86 0.5817 20090408225650c
8.0 150 25 -80 5.23 0.4614 20090409005259
7.0 155 30 -75 5.11 0.4963 20090409005259a
8.0 155 30 -75 5.22 0.4861 20090409005259b
7.0 325 50 -90 5.22 0.5524 20090409005259c
16.0 330 85 -55 4.33 0.5379 20090409031452
13.0 150 90 55 4.17 0.5035 20090409031452a
14.0 150 90 60 4.28 0.5633 20090409031452b
12.0 150 90 55 4.20 0.5897 20090409031452c
11.0 15 65 -30 4.19 0.3879 20090409043244
8.0 10 60 -35 4.04 0.4199 20090409043244a
10.0 10 60 -35 4.15 0.4094 20090409043244b
7.0 5 55 -45 4.11 0.4437 20090409043244c
8.0 160 50 -60 4.99 0.3046 20090409193816
6.0 315 45 -95 4.88 0.3286 20090409193816a
8.0 150 40 -75 4.99 0.3248 20090409193816b
7.0 135 45 -95 4.98 0.3778 20090409193816c
4.0 135 45 -75 3.67 0.4350 20090410032222
4.0 130 45 -85 3.65 0.4441 20090410032222a
4.0 135 45 -80 3.64 0.4441 20090410032222b
5.0 305 45 -95 3.74 0.4736 20090410032222c
9.0 155 55 -80 4.89 0.4628 20090413211424
6.0 335 35 -80 4.76 0.5281 20090413211424a
8.0 330 35 -90 4.87 0.4898 20090413211424b
6.0 335 30 -80 4.85 0.5805 20090413211424c
9.0 175 50 -55 3.82 0.5304 20090414201727
7.0 170 50 -65 3.70 0.5725 20090414201727a
9.0 160 45 -75 3.82 0.5583 20090414201727b
7.0 330 45 -90 3.79 0.6535 20090414201727c
8.0 160 50 -65 3.88 0.4392 20090415225307
6.0 330 40 -80 3.86 0.5594 20090415225307c