Welcome to our research "lab" that houses 50 modern, self-contained seismometers ("nodes") from FairfieldNodal.
A seismometer is a very sensitive instrument that is placed in the ground and detects very small movements resulting from the passage of seismic waves. With these recordings we are able to image beneath the Earth's surface, study earthquake sources, and monitor subtle changes in the subsurface such as aquifer recharge that are usually difficult to detect.
In mid-July 2018, our INGV* team comprised of Francesca Di Luccio, Luigi Cucci and Alessandra Esposito scouted the locations of our instruments on Lipari Island. We will deploy the nodes in early October 2018 and record ambient noise and local seismicity over a time period of 35 days. The array will have a roughly semicircular geometry in and around the hydrothermal area, with the final configuration determined strictly by the topography. Seismic data will be merged with the surface lithology, faults and fractures, and volcanic structures mapped during the seismic acquisition, and interpreted along with measurements of the CO2 gas flux from the study area. The combined analysis of simultaneous measurements of CO2 gas release and seismic properties will provide information on the dynamics of fluid ascent and pathways. Results from this study will improve our understanding of the fluid dynamics at shallow depth and the unrest episodes in active volcanic and hydrothermal areas.
More information on the project can be found here.
*National Institute of Geophysics and Volcanology, Rome, Italy
We were back in the Los Angeles area this summer to add three new seismic profiles across the San Bernardino basin.
Our 2018 deployment team (photo in the lower left) included volunteers from the Jet Propulsion Lab, Cal Poly Pomona, the USGS, USC, LSU and Caltech.
Read Phys.org news article about our study at this link and our new SRL article.
The vertical component of a local earthquake (M 2.7) recorded along Line 2 of our seismic experiment. The map below shows the locations of the three profiles in our final deployment. We deployed Lines 1 and 2 across the San Gabriel basin, and Line 3 across the Chino basin. The northwestern end of Line 2 is located near the Rose Bowl in Pasadena, CA.
In one month, we were able to record at least two clear teleseismic earthquakes that are useful for producing high-resolution receiver functions. The vertical and east components of one of these teleseismic events (M 6.5) are shown in the two figures below. More data from our experiment can be viewed at Rob Clayton's page.
The nodes are back from their San Gabriel basin deployment. Our group deployed a total of 199 of these small, compact, cable-free seismic instruments in the San Gabriel basin, Southern California with a spacing of ~300 m. 50 nodes were from LSU, 60 from the PASSCAL Instrument Center, and 89 from the University of Utah. The nodes were deployed in an urban environment - in people's backyards, in parks, at the sides of roads and in a golf course. In five teams of 12 people total, LSU's 50 nodes were deployed in about 3 hours.
While Arlen worked on dowloading the data and recharging the nodes, Jessica presented our work at LSU Discover Day. See the larger poster here.
We have started to select recordings of teleseismic earthquakes for our receiver function computations. Our objective is to identify the basement contact and basin shape.
We are excited about our first deployment of the nodes, which will be in the San Gabriel basin in the Los Angeles metropolitan area as part of a collaborative project. This is preliminary work, and will be followed by subsequent deployments. The group's overall objective is to investigate the amplification of ground motion from a potential earthquake rupture on the southern San Andreas Fault. Our instruments will be deployed for 35 days, and will continuously record earthquakes and ambient noise (video link).Feb 19, 2017 - G&G students in the field deploying seismometers near the San Andreas Fault, Southern California - Twitter Link.