Heterogeneous response of hydrogeological systems to the Izmit and Düzce (Turkey) earthquakes of 1999

Groundwater level changes induced by the 2011 Tohoku earthquake in China mainland

“…According to the enhanced permeability model, sustained groundwater level changes induced by distant earthquakes might be expected at sensitive sites, usually located on active faults, especially on the intersections or bends characterized by subcritical hydrogeological conditions (King et al 2006). The heterogeneous distribution of sustained groundwater level change suggests that the sensitivity and hydrogeological conditions are really site-specific (Woith et al 2003) and thus the response to earthquakes may differ even within small regions. However, statistical results indicated that falling water levels induced by the Tohoku earthquake correlated to some degree with a falling trend preceding the earthquake (Fig.…”

“…In gas-saturated aquifers, seismic waves may trigger the rise of gas bubbles and thus increase the pressure locally according to the mechanism of advective overpressure (Steinberg et al 1989). A co-and post-seismic flow-rate increase of the order of 25 per cent, observed at an artesian well about 1400 km from the epicentre of the 1999 Izmit earthquake, may be explained this way (Woith et al 2003;Wang et al 2004). Brodsky et al (2003) investigated step-like coseismic groundwater level changes and proposed a model based on the removal of barriers clogging the groundwater flow dynamically induced by seismic waves of distant earthquakes.…”

Seismically induced shale diapirism: the Mine d’Or section, Vilaine estuary, Southern Brittany

“…An external trigger for liquefaction and a complementary water supply were obviously needed here to explain it. As water is a non-compressible fluid, the alternating squeezing and suction from the local water table in the faulted basement that were caused by vibrations rise in excess pore water pressure (Woith et al 2003). This advective overpressure with subsequent liquefaction needed to reach a minimum 1.5 bar (overburden weight) in the overlying saprolite.…”

Palaeolimnology of Lake Sapanca and identification of historic earthquake signals, Northern Anatolian Fault Zone (Turkey)

“…1) changed the conductivity of water in a well ~1400 km away from the epicentre. However, conductivity levels did not change in wells ~300-1200 km from the epicentre, due to differences in geology (Woith et al, 2003) and it is not known whether the water chemistry of Lake Sapanca changed during these earthquakes. Another possible earthquake-related limnological change in Lake Sapanca is an increase in nutrient levels caused by mobilisation of nutrients from sediments in the lake or its catchment.…”

“…Seepage of hydrothermal fluids along a fault located below the sea may lead to salinity or pH changes in the water during or after an earthquake (Claesson et al, 2004;Kuşçu et al, 2005). However, the local hydrogeological setting determines whether any change occurs at all (Sneed et al, 2003;Woith et al, 2003). For example, the 1999 earthquakes in northwest Turkey (Fig.…”