Showing papers by "James Goff published in 2006"

Sri Lanka Field Survey after the December 2004 Indian Ocean Tsunami

Abstract: In August 2005, a team surveyed the effects of the December 2004 Indian Ocean tsunami on the southern coast of Oman. Runup and inundation were obtained at 41 sites, extending over a total of 750 km of shoreline. Measured runup ranged from 3.25 m in the vicinity of Salalah to a negligible value at one location on Masirah Island. In general, the largest values were found in the western part of the surveyed area. Significant incidents were documented in the port of Salalah, where a 285-m-long vessel broke its moorings and drifted inside and outside the port, and another ship struck the breakwater while attempting to enter the harbor. The general hazard to Oman from tsunamis may be greatest from the neighboring Makran subduction zone in western Pakistan.

Coastal dune ridge systems as chronological markers of palaeoseismic activity : a 650-yr record from southwest New Zealand

Abstract: A study of two shore-parallel dune ridge sequences in southwest New Zealand shows that tectonic activity has been the primary controlling influence in their formation since at least AD 1450. The timing of dune-building episodes at the mouths of the Haast and Okuru Rivers was determined using the ages of colonizing trees. Episodic dune formation was indicated by clear discontinuities in tree ages, with distinct cohorts having colonized successive, newly formed, dune ridge-swale units. At both sites, four dune ridge-swale units have formed since AD 1450, with each unit closely postdating an Alpine fault rupture (c. AD 1460, c. AD 1615, AD 1717, AD 1826). Colonizing cohorts of trees started growing within 20-46 years after an earthquake at both sites, and all known major regional earthquakes have resulted in a dunebuilding episode. No other dunes are present at either site. Progradational coastal dune systems have potential as a tool for palaeoseismic studies. In regions with high background levels of sedime...

Locally generated tsunami along the Kaikoura coastal margin: Part 2. Submarine landslides

Abstract: An examination of the underwater landscape along the northeast coast of the South Island, New Zealand, identified a substantial potential for a submarine landslide in Kaikoura Canyon. A numerical model was applied to calculate runup and inundation arising from a local tsunami generated by such a landslide. The model is based on the Reynolds‐averaged Navier‐Stokes (RANS) equation and used a finite element spatial approximation, implicit time integration, and a semi‐Lagrangian advection approximation. The results indicate that a landslide‐generated tsunami represents a large potential hazard to the area from South Bay to Oaro, South Island, New Zealand, and has the potential to generate large tsunami runup heights along this section of coast. In addition, the tsunami events are characterised by a short time interval between generation and runup.

Tsunamigenic sources in the bay of plenty, new zealand

Abstract: New Zealand sits in a precarious position astride the boundary between the Pacific and Australian Plates. There is a wide range of potential tsunamigenic sources in this area including fault movements, submarine landslides, volcanic activity, and other mechanisms. In addition, considerable prehistoric information indicates that large tsunamis have inundated the coastline several times in the past. A part of our work has been directed toward using historic and prehistoric tsunami data to evaluate possible sources. Several types of dislocation models and submarine landslide models are used to simulate the displacement of the sources. A finite element numerical model is used to simulate generation, propagation and runup of the resultant tsunami. As an example, we present results for the Bay of Plenty, northeast coast of the North Island, New Zealand. The range of source types includes local faults, subduction zone rupture, volcanic eruptions, sector collapse of seamounts, and submarine landslides. A likely major source is a subduction zone event along the Tonga-Kermadec Trench. Data from paleotsunami deposits have guided the model in determining appropriate source characteristics and establishing the most significant event for this region.

Locally generated tsunami along the Kaikoura coastal margin: Part 1. Fault ruptures

Abstract: Tsunami are generated by sudden movements of the ocean bed or by objects such as subaerial landslides and bolides falling into the ocean. An examination of the geophysical setting for the northeast coast of the South Island, New Zealand, identified a substantial potential for submarine fault ruptures and submarine landslides. To examine possible effects of a tsunami, a numerical model was applied to calculate runup and inundation arising from locally‐generated tsunami along this section of the coast. The specific events considered were fault ruptures on the Kekerengu Bank Fault and two lesser faults, and a submarine landslide in Kaikoura Canyon. The model is based on the Reynolds‐averaged Navier‐Stokes (RANS) equation and used a finite element spatial approximation, implicit time integration, a semi‐Lagrangian advection approximation, and a simple method for treating non‐hydrostatic pressure variations. The results indicate that the different generation events have significant effects on differen...