GPS instruments are noninertial and directly measure displacements with respect to a global reference frame, while inertial sensors are affected by systematic offsets—primarily tilting—that adversely impact integration to displacement. We study the magnitude scaling properties of peak ground displacement (PGD) from high‐rate GPS networks at near‐source to regional distances (~10–1000 km), from earthquakes between M_w6 and 9. We conclude that real‐time GPS seismic waveforms can be used to rapidly determine magnitude, typically within the first minute of rupture initiation and in many cases before the rupture is complete. While slower than earthquake early warning methods that rely on the first few seconds of P wave arrival, our approach does not suffer from the saturation effects experienced with seismic sensors at large magnitudes. Rapid magnitude estimation is useful for generating rapid earthquake source models, tsunami prediction, and ground motion studies that require accurate information on long‐period displacements.

We processed data from ~100 continuous GPS stations to provide new insights into the crustal motion and deformation of central and western Greece. We used the derived velocity field to evaluate two‐dimensional strain and rotation rate tensors, and we mapped the dilatation and maximum shear strain rates. In central Peloponnese and Epirus, we documented a 90° switch in the extension direction, which can be explained on the basis of the plate boundary configuration. Evidence for an extended deformation pattern in central Greece was found. Additionally, we detected two pairs of shear belts, one in Akarnania‐NW Peloponnese and one in North Aegean. We delineated two rotational domains that dominate the present‐day pattern. Moreover, we saw no geodetic evidence for North Anatolian Fault growth toward central Greece. We translated the geodetic strain rates into rates of seismic moment release and compared them with earthquake catalog‐based moment rates. In the central Ionian Sea, the geodetic strain is completely released seismically, which is indicative of a fully coupled seismogenic zone. However, for most of the study area, the geodesy‐based moment rates are at least 2 times higher than the earthquake‐based rates. We attribute this mainly to earthquake catalog representativity over the long‐term situation. However, for the Gulf of Corinth, it is unrealistic to associate the high ratio of geodetic to seismic moment rates only to incompleteness of the earthquake catalog; instead, long‐term aseismic deformation must be an important mechanism accommodating a considerable portion of the strain budget, especially at its western part.

We present new field data from rivers draining across active normal faults that incise across the same lithology at the fault, have been subjected to similar climatic regimes and tectonic settings, and were perturbed by a well-documented increase in fault slip rate ca. 1 Ma. In spite of these similarities, the rivers exhibit markedly different long profiles and patterns of catchment incision. We use channel slope and hydraulic geometry data for each river to calculate bed shear stresses (τb), and show that there is no simple relationship between peak τb and the relative uplift rates across the faults, U, which differ by a factor of four. The long-term average sediment supply to each channel (Qs), estimated from time-averaged catchment erosion rates, can explain the τb versus U data if bedload modulates bedrock incision rate, E, in a strongly nonlinear way. Together these field data allow us, for the first time, to evaluate theoretical predictions of the role of sediment on river profile evolution and to quantify the magnitude of the effect in natural systems