Fig 1.
Tectonic setting, observed land-level changes and plate-boundary slip during the Iquique earthquake.
Stars indicate epicentres of the mainshock and major aftershock [25]. Squares denote location of the benchmarks, campaign GPS and intertidal biota sites studied, while diamonds indicate location of continuous GPS stations used in this study (S1 Table). Color-coded by static uplift (see text for details). Arrows in inset show plate convergence at ~ 66 mm/yr.
Table 1.
Times of data collection at the sites where benchmarks (X) were measured and GPS mobile stations were installed for field campaigns (●).
Table 2.
Pre—earthquake and post—earthquake elevations levels (cm) of benchmarks along rocky shores of northern Chile.
Statistical differences were assessed by using a one sample t—test, considering the value (H1, n1 = 1) recorded during the pre—earthquake period as a constant, compared to data recorded during the post—earthquake period (H2; n2).
Table 3.
Pre—earthquake to post—earthquake differences in shore elevation measured by levelling (elevation of benchmarks), campaign and continuous GPS stations.
Values in parentheses are standard deviations for benchmarks and standard errors for the data of campaign and continuous GPS.
Fig 2.
Comparison of land level changes estimated during May 2014 using measurements of benchmarks with respect to surveyed tidal datums and campaign GPS.
Fig 3.
Comparison of land level changes estimated during April, May, June and August 2014, using surveyed benchmarks and continuous GPS stations.
Averaged weekly positions were estimated from daily solutions of the continuous GPS data for benchmark surveying periods.
Fig 4.
Time series of land-level changes estimated from daily positions of continuous GPS used in this study.
The thick black line marks the time of the 2014 Pisagua earthquake. The red and black lines show trajectory models calculated to separate epochs before and after the earthquake. Green lines mark Heaviside jumps either caused by local earthquakes or antenna changes. Blue lines mark the dates when benchmarks and rocky shore biota were surveyed. See Fig 1 for location of the sites.
Table 4.
Pre–earthquake and post-earthquake upper limits (cm) for sessile rocky shore species and estimated change (ΔH) in elevation between pre—earthquake and post—earthquake periods at Pisagua and Chanavaya.
Each ΔH estimate was based on 1000 independent simulated values. M = mean, SD = standard deviation.