These barometric pumping mechanisms will be enhanced by the presence of fractures, which permit pressure variations to propagate deep into the ground.
In pressure pulse testing, a pressure signal generated by periods of injection and shut-in (from a pulsing well) propagates deep into the formation, and the corresponding response is recorded at the observation well(s).
Ping He [4] demonstrates in his study that a Gaussian pulse propagating in soft tissues could also be modeled as a Gaussian pulse with parameters changing as the pulse propagates deep within tissue.
When the ultrasonic pulse propagates deep within material ( -axis), then, it was demonstrated in [4] that for an attenuation law of the form (with, or ), the previous expression can be reformulated as (2).
It should be noted that, when determining from w the pore formation rate in the tangential directions parallel to the substrate plane, we neglect the possible influence exerted on this rate by the front of the electrochemical process, which freely propagates deep into the crystal and is nonuniform in its characteristics (for more details, see [13]).
The similarities between mesoscale flow channels in the dayside cusp and within the nightside polar cap, as well as the patch propagation from the dayside to nightside polar cap, suggest that mesoscale fast flows in the dayside oval propagate deep into the polar cap (Wilder et al. 2012 and references therein).
Some polar cap patches have been shown to propagate deep into the polar cap and reach the nightside polar cap (Oksavik et al. 2010), and they can even exit the polar cap through magnetic reconnection and enter the nightside auroral oval (Zhang et al. 2013b).
Although uncertainty of a few kilometers may exist because of insufficient information regarding the detailed velocity structure, the depth of 18 km is consistent with the results of source process analyses (Koketsu 2016; Asano and Iwata 2016; Nozu 2016) that suggest that the rupture propagated deep near the hypocenter.
Claims grew that the event would merely propagate deep-rooted Western- held stereotypes of a hapless continent rather than a vibrant land which wanted to help itself as desperately as it required assistance.
On the other hand, seismic observation since the morning of June 29 indicates that the main hypocentral area of the high-frequency seismicity started around a depth of 0 km and gradually propagated deeper (Fig. 16).
