Publications

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2015
Fiedler, JW, Brodie KL, McNinch JE, Guza RT.  2015.  Observations of runup and energy flux on a low-slope beach with high-energy, long-period ocean swell. Geophysical Research Letters. 42:9933-9941.   10.1002/2015gl066124   AbstractWebsite

The transformation of surface gravity waves from 11 m depth to runup was observed on the low-sloped (1/80) Agate Beach, Oregon, with a cross-shore transect of current meters, pressure sensors, and a scanning lidar. Offshore wave heights H-0 ranged from calm (0.5 m) to energetic (> 7 m). Runup, measured with pressure sensors and a scanning lidar, increases linearly with (H0L0)(1/2), with L-0 the deep-water wavelength of the spectral peak. Runup saturation, in which runup oscillations plateau despite further increases in (H0L0)(1/2), is not observed. Infragravity wave shoaling and nonlinear energy exchanges with short waves are included in an infragravity wave energy balance. This balance closes for high-infragravity frequencies (0.025-0.04 Hz) but not lower frequencies (0.003-0.025 Hz), possibly owing to unmodeled infragravity energy losses of wave breaking and/or bottom friction. Dissipative processes limit, but do not entirely damp, increases in runup excursions in response to increased incident wave forcing.

2014
Fiedler, JW, McManus MA, Tomlinson MS, DeCarlo EH, Pawlak GR, Steward GF, Nigro OD, Timmerman RE, Drupp PS, Ostrander CE.  2014.  Real-time observations of the February 2010 Chile and March 2011 Japan tsunamis recorded in Honolulu by the Pacific Islands Ocean Observing System. Oceanography. 27:186-200.   10.5670/oceanog.2014.34   AbstractWebsite

Continuous monitoring by the Pacific Islands Ocean Observing System (PacIOOS) provided a unique opportunity to study the effects of two tsunamis on the coastal and estuarine waters of Hawaii. By the time the 2010 Chile and 2011 Japan tsunamis reached the waters of southern O'ahu, they had lost much of their power (both were < 1 m high in Honolulu Harbor). Nevertheless, their effects on the surrounding waters were profound, with increases observed in near-bed current velocities, mixing in estuarine waters, salinity, turbidity, chlorophyll, and pathogenic bacteria such as Vibrio spp. In addition to these increases, we observed small decreases in nitrate and dissolved oxygen concentrations offshore, including a dampening of the normal diel cycle in dissolved oxygen. Some of the effects penetrated canals as far as 1 kin inshore and could be observed up to 0.5 km offshore. Data from the PacIOOS sensors and our sampling show that altered and potentially degraded water quality can persist longer than the physical threat from surge. Shortly after both tsunamis, the "all clear" signal was given and people resumed recreational activities in coastal waters before our data indicated recovery of healthy water quality conditions. Following such events, monitoring should be expanded and continued in order to accurately characterize water quality and evaluate potential public health risks.