Text · collection · 2008
Shear Wave Structure of Umbria and Marche, Italy, Strong Motion Seismometer Sites Affected by the 1997-98 Umbria-Marche, Italy, Earthquake Sequence
Listed in NASA Earthdata CMR
A long sequence of earthquakes, eight with magnitudes between 5 and 6, struck the Umbria and Marche regions of central Italy between September 26, 1997 and July 1998.
Description
The earthquake swarm caused severe structural damage, particularly to masonry buildings, and resulted in the loss of twelve lives and about 150 injuries. The source of the events was a single seismogenic structure that consists of several faults with a prevailing northwest-southeast strike and crosses the Umbria-Marche border.
The focal mechanism of the largest shocks indicates that the events were the product of shallow extensional normal faulting along a NE-SW extension perpendicular to the trend of the Apennines. The network of analog seismometer stations in the Umbria and Marche regions recorded motions of the main September and October 1997 events and a dense array of mobile digital stations, installed since September 29, recorded most of the swarm.
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The permanent national network Rete Accelerometrica Nazionale (RAN) is administered and maintained by Dipartimento delle Protezione Civile (DPC: Civil Protection Department); the temporary array was managed by Servizio Sismico Nazionale (SSN) in cooperation with small agencies and Universities (SSN, 2002). Most of the temporary and permanent stations in the Italian seismic network have little or no characterization of seismic velocities.
In this study, we investigate 17 Italian sites using an active-source approach that employs low frequency harmonic waves to measure the dispersive nature of surface waves in the ground. We use the Spectral Analysis of Surface Wave (SASW) approach, coupled with an array of harmonic-wave electro-mechanical sources that are driven in-phase to excite the ground. An inversion algorithm using a non-linear least-squares best-fit method is used to compute shear wave velocities for the upper 100-200 meters of the soil column.
[Summary provided by the USGS.]
Links
Get the data
- pubs.usgs.gov /of/2008 ↗
Report and data on Shear Wave Structure of Umbria and Marche, Italy, Strong Motion Seismometer Sites Affected by the 1997-98 Umbria-Marche, Italy, Earthquake Sequence.
download · from NASA CMR
Catalogue records · 2
- CMR record cmr.earthdata.nasa.gov/search/concepts/C2231548598-CEOS_EXTRA.html ↗
catalogue entry · from NASA CMR
- CMR UMM-JSON cmr.earthdata.nasa.gov/search/concepts/C2231548598-CEOS_EXTRA.umm_json ↗
metadata API · from NASA CMR
Topics
- Stated by source
- Earthquake Magnitude/Intensity · Earthquake Occurrences · SEISMOLOGICAL STATIONS · SEISMOMETERS
Provenance · 1 source records, 11 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| NASA Earthdata CMR | C2231548598-CEOS_EXTRA | 8 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[instrument].gcmd_instrument:seismometers | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/solid-earth/tectonics/earthquakes/earthquake-magnitude-intensity | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[measured_variable].gcmd:earth-science/solid-earth/tectonics/earthquakes/earthquake-occurrences | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| concepts[platform].gcmd_platform:seismological-stations | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| description | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/Abstract |
| publication_date | source · NASA CMR | connector:nasa_cmr@1.0.0 | |
| spatial | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/SpatialExtent |
| temporal | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/TemporalExtents |
| title | source · NASA CMR | connector:nasa_cmr@1.0.0 | /umm/EntryTitle |
| version_label | source · NASA CMR | connector:nasa_cmr@1.0.0 |