@InProceedings{MarquesAssuPadiPádu:2018:AsSoAm,
               author = "Marques, Haroldo Antonio and Assump{\c{c}}{\~a}o, Marcelo and 
                         Padilha, Ant{\^o}nio Lopes and P{\'a}dua, Marcelo Banik de",
          affiliation = "{Instituto Militar de Engenharia (IME)} and {Universidade de 
                         S{\~a}o Paulo (USP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)}",
                title = "Assessment of South America mid-plate strain rates through GNSS 
                         velocities estimated from SIRGAS-C time series",
                 year = "2018",
         organization = "AGU Fall Meeting",
             abstract = "We are investigating terrain deformations of long range and 
                         persistence that take place on continental scale over the stable 
                         shield of continental South America. The crustal deformation is 
                         being investigated by correlating with velocities and directions 
                         obtained from time series of approximately 60 GNSS stations 
                         deployed in Brazil and neighboring countries that take part of the 
                         Continuous network of the Geocentric Reference System for the 
                         Americas (SIRGAS-C). We attempt to estimate velocities and 
                         mid-plate strain rates using the best GNSS stations located in the 
                         stable South America mid-plate. The velocities have been estimated 
                         by Least Square Estimation (LSE) using SIRGAS weekly time series 
                         with a stochastic model composed of white noise plus flicker or 
                         random walk noises. Variance Component Estimation (VCE; 
                         Amiri-Simkooei et al., 2007) has been applied to classify the type 
                         of noise and compose the time series stochastic model. In 
                         addition, the time series breaks and offsets are taken into 
                         account in the LSE. The noises were classified as white plus 
                         flicker noise in approximately 70% of the horizontal component and 
                         most of random walk appears for stations located in the Amazon and 
                         Pantanal basins or near the coastal zones. The estimated formal 
                         precision reach about 0.10 mm/year with RMS of residual near 1.5 
                         and 4.5 mm respectively for horizontal and vertical velocities. 
                         The estimated velocities by LSE were also computed by using the 
                         MIDAs code (Blewit et al 2015) and the results show an agreement 
                         of the order of 0.30 mm/y. The computed strain rates in the 
                         central part of Brazil indicate shortening, consistent with the 
                         predominance of reverse faulting mechanisms. When a station pair 
                         includes one station near the coast, the linear strain rates 
                         indicate extension. However, strain rates do not clearly indicate 
                         a preferred principal direction and do not seem compatible with 
                         the stress patterns derived from the focal mechanisms. In 
                         addition, the rate of seismic moment release indicates strain 
                         rates from earthquake occurrence two to three orders of magnitude 
                         lower than the observed strain rates from the geodetic network. 
                         Assessment of South America linear strain rates computed through 
                         estimated GNSS velocities will be discussed.",
  conference-location = "Washington, D. C.",
      conference-year = "10-14 dec.",
             language = "en",
                  ibi = "8JMKD3MGP3W34R/3SB3DDH",
                  url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3SB3DDH",
           targetfile = "marques_assessment.pdf",
        urlaccessdate = "27 abr. 2024"
}