Julia W Fiedler

• PhD
• PostDoc Position at University of California, San Diego

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 H0 ranged from calm (0.5 m) to energetic (>7 m). Runup, measured with pressure sensors and a scanning lidar, incr...

1] Dams have impounded ∼10,800 km 3 of water since 1900, reducing global sea level by ∼30.0 mm and decreasing the rate of sea level rise. The load from impounded water depresses the earth's surface near dams and elevates the geoid, which locally increases relative sea level (RSL). We computed patterns of dam‐induced RSL change globally, and estimat...

Runup on ocean beaches includes steady wave setup and oscillating swash, often decomposed into wind generated sea-swell (SS), and lower frequency infragravity (IG) waves. We show that the numerically fast, open-source numerical model 1D SWASH predicts accurately the bulk properties of runup observed on two natural beaches (one steep and one shallow...

Numerical models predicting surfzone waves and shoreline runup in field situations are often initialized with shoreward propagating (sea-swell, and infragravity) waves at an offshore boundary in 10–30 m water depth. We develop an offshore boundary condition, based on Fourier analysis of observations with co-located current and pressure sensors, tha...

Accurate observations of the nearshore bathymetry, including within the breaking wave region, are critical for the prediction of coastal hazards, and improved understanding of sandy beach morphological response to storms. In this paper, we implement the recent Boussinesq theory-based depth inversion methodology of Martins et al. (Geophys. Res. Lett...

Numerical predictions of nearshore waves and shoreline runup are usually initialized on the inner shelf, seaward of the surfzone, with sea‐swell (SS) waves from local wave buoys or regional wave models. Lower frequency infragravity (IG) waves are not reliably measured by buoys or included in regional models. Here, co‐located pressure and velocity o...

Understanding and predicting changes in shoreline location are critical for coastal planners. In situ monitoring is accurate but not widely available. Satellite observations of shorelines have global coverage, but their accuracy and predictive capacity have not been fully explored. Abundant beach surveys and extensive wave observations in Southern...

Co-located pressure and velocity observations in 10-15m depth are used to estimate the relative contribution of bound and free infragravity (IG) wave energy to the IG wave field. Shoreward and seaward going IG waves are analyzed separately. At the Southern California sites, shoreward propagating IG waves are dominated by free waves, with the bound...

Time series of storm wave runup and overtopping observed on a sandy beach with a scanning LiDAR are compared with predictions of the phase-resolving numerical model SWASH 1D. SWASH is initialized 300 m offshore (8-m depth) with phase-resolved estimates of shoreward and seaward propagating waves, observed with a co-located pressure sensor-current me...

Wave runup estimates are used in erosion and overtopping models, and in coastal structure design. However, runup depends on often incompletely known surf and swash bathymetry. The many existing runup parameterizations characterizing bathymetry with only the foreshore (swash zone) beach slope βf are necessarily of limited accuracy. Here, an empirica...

We demonstrate that a hovering, drone-mounted laser scanner (LiDAR) paired with a survey-grade satellite and inertial positioning system measures the wave transformation across the surf zone and the resulting runup with accuracy almost equal to a stationary truck-mounted terrestrial LiDAR. The drone, a multi-rotor small uncrewed aircraft system (sU...

Waves overtop berms and seawalls along the shoreline of Imperial Beach (IB), CA when energetic winter swell and high tide coincide. These intermittent, few-hour long events flood low-lying areas and pose a growing inundation risk as sea levels rise. To support city flood response and management, an IB flood warning system was developed. Total water...

Storm wave run-up causes beach erosion, wave overtopping, and street flooding. Extreme runup estimates may be improved, relative to predictions from general empirical formulae with default parameter values, by using historical storm waves and eroded profiles in numerical runup simulations. A climatology of storm wave run-up at Imperial Beach, Calif...

Seismic signals from ocean‐solid Earth interactions are ubiquitously recorded on our planet. However, these wavefields are typically incoherent in the time domain limiting their utilization for understanding ocean dynamics or solid Earth properties. In contrast, we find that during large storms such as hurricanes and Nor'easters the interaction of...

No PDF available ABSTRACT We have discovered a new geophysical phenomenon involving the coupling of the atmosphere-ocean and solid Earth using a novel array method. An analysis of ten years of seismic data recorded in the continental United States, mainly at the USArray, shows that large storms such as hurricanes and Nor’easters can excite transien...

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 Hawai'i. 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...

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 Hawai'i. 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...

PacIOOS, with 24/7 all-weather coverage, provides us with immediate, real-time data to investigate the effects of various phenomena including land-based storms and associated runoff, offshore storms, and tsunamis. We have been able to study the temporal and spatial distribution of water quality effects of storm runoff on the nearshore zone with the...