Final NATS 1750 Fall 2016 Assignment 1 Version 10

Final Nats 1750 A Fall 2016 Assignment 1 Version 10 Oc

Obtain a credible, journalistic account of coastal flooding caused by Hurricane Matthew’s storm surge at a specific, geographic location, including a quantitative estimate of the flooding. Provide an elevation estimate (relative to MSL) for your specific location, citing the source. Using this elevation estimate, indicate your location on an annotated hypsometric curve. On this curve, mark the extent of flooding. If this flooding represented a global sea-level change, estimate the impacted land area and its percentage of total land surface. Extract factors that may have influenced storm surge height for your location: shelf slope, storm intensity, forward speed, radius, approach angle, coastline landscape, and storm tides, explaining each factor’s effect. Create a process flow diagram illustrating the storm surge source and three sinks with processes.

Using a map, measure the distance from the big island of Hawaii to Kauai, and, knowing Kauai’s age (5.1 million years), calculate the Pacific Plate’s rate of movement in cm/yr. Repeat with Lanai (age 1.28 million years). Determine if this rate has increased, decreased, or remained stable, justifying your conclusion. Describe the age-distance trend for Hawaiian Islands, supporting it with quantitative data. Estimate the distance of a hypothetical 15 Ma island from Kilauea using this trend, and the age of a seamount 5325 km from Kilauea. Decide on the most suitable Hawaiian Island for a geothermal plant based on geothermal energy potential.

Sample Paper For Above instruction

Introduction

The coastal effects of hurricanes, particularly storm surges, pose significant threats to coastal regions worldwide. Hurricane Matthew in 2016 exemplified such a natural hazard, causing extensive flooding along the southeastern United States. This paper explores the flooding caused by Hurricane Matthew through a case study centered on a specific geographic location, integrating quantitative data and geophysical concepts such as hypsometric curves and plate tectonics. The analysis aims to understand how storm surge height correlates with elevation, how various factors influence surge magnitude, and how the Hawaiian Island chain's formation relates to plate movement. The report is structured into sections covering storm surge assessment, hypsometric curve application, land impact estimation, and plate tectonics analysis, culminating in recommendations for geothermal energy development.

Hurricane Matthew’s Coastal Flooding: A Case Study

Hurricane Matthew made landfall in October 2016, affecting the southeastern coast of the United States, particularly South Carolina. According to a report from the National Hurricane Center (2016), Matthew generated a significant storm surge of approximately 2.5 meters (8 feet) along the coast near Charleston. This surge resulted in substantial coastal flooding, inundating low-lying areas such as the Charleston Peninsula and surrounding regions. The account from Live Science (Geggel, 2016) estimates that roughly 50 square miles (130 km²) of land were affected by the flooding, with water levels exceeding normal high tide levels, thereby causing both temporary inundation and long-term infrastructural impacts. The flood extent was notably influenced by the storm’s intensity, approach angle, and the local topography.

Elevation Estimate of the Geographic Location

The primary site of flooding, Charleston, is located approximately at an elevation of 3 meters (10 feet) above Mean Sea Level (MSL), according to NOAA topographic data (NOAA, 2016). This relatively low elevation made the area especially vulnerable to storm surge. By correlating the storm surge height (2.5 meters) with this elevation, it is evident that even modest surges can substantially impact low-lying coastal zones.

Hypsometric Curve Analysis

Referring to the coastal hypsometric curve (Eakins & Sharman, 2012), Charleston’s elevation position falls near the lower end of the curve, indicating that most of the coastline's land area lies at low elevations. Using the hypsometric curve, the elevation estimate of 3 meters corresponds to a specific percentage of the world's land surface at or below this elevation, roughly 15%. Plotting this point on the curve illustrates the vulnerability of such low-lying regions to storm surges.

Extent of Flooding on the Hypsometric Curve

The recorded flood impacts at Charleston align with the flood extent indicated on the hypsometric curve—namely, the inundation of areas where elevation is below approximately 4 meters. The flood likely affected a significant portion of land at these elevations, corresponding to a notable percentage of the total coastal land area, thereby emphasizing the importance of elevation in flood susceptibility.

Global Sea Level Rise and Land Area Loss

Assuming the extent of flooding reflects a global sea-level rise, the affected land area can be scaled up to the planetary level. With the Earth's total land surface of approximately 150 million km² and an assumed sea level rise of 0.5 meters, calculations suggest that about 0.03% of land (around 45,000 km²) could be affected globally by similar surges. The percentage loss of land at this global scale would be correspondingly small but significant for localized coastlines.

Factors Affecting Storm Surge Heights

Geggel (2016) identified several factors influencing storm surge height:

• Slope of the Continental Shelf: A gentler slope of the continental shelf near Charleston facilitated the amplification of storm surge, as shallow waters allow storm energy to pile up, raising water levels. The shelf here is notably broad and shallow, explaining the high surge impact (NOAA, 2016). The shelf’s slope is absent from histograms because hypsometric curves typically depict global land elevations, not oceanic shelf slopes.
• Storm Intensity: Hurricane Matthew was a Category 5 hurricane at peak intensity, directly correlating with high storm surge height due to increased wind speeds and storm pressure drops.
• Forward Speed of the Hurricane: Slower-moving storms tend to generate higher surges because they exert prolonged pressure on the coast. Matthew’s forward speed near the landfall was moderate, contributing to surge height.
• Radius of the Storm: A larger storm radius increases the area affected by high winds, thereby raising surge levels.
• Approach Angle: A more oblique approach to the coast enhances surge inundation inland, especially if the storm’s eye approaches at a shallow angle.
• Coastal Landscape: Low-lying, flat coastal topography enhances flooding potential, whereas cliffs and substantial elevation gradients reduce flood impact.
• Storm Tides: The astronomical tide at the time of surge peak compounded the flooding, illustrating the combined effect of storm tides and surge.

Process Flow Diagram of Storm Surge Dynamics

The storm surge originates from the low-pressure system of the hurricane, creating a bulge of water. This water then moves inland, driven by wind and pressure gradients, encountering various sinks such as:

1. Inundation of low-lying coastal plains through wave and current action.
2. Overflow into estuaries and bays, affecting aquatic ecosystems and human settlements.
3. Runoff into the ocean, counteracting inland flooding but contributing to coastal erosion.

The process involves energy transfer from wind to water, followed by inundation, overtopping, and eventual dissipation through wave breaking and gravity-driven flow into the ocean.

Plate Movement and Hawaiian Islands Formation

Measuring the distance between the Big Island of Hawaii and Kauai, approximately 300 km, and considering Kauai’s age (5.1 Myr), the Pacific Plate's rate of movement can be calculated as follows:

• Rate = Distance / Age = 300 km / 5.1 Myr ≈ 58.82 km/Myr.
• Converting to cm/yr: (58.82 km / Myr) × (100,000 cm / km) / (1,000,000 yr / Myr) ≈ 5.88 cm/yr.

Similarly, the distance to Lanai, at about 220 km, and its age (1.28 Myr), yields:

• Rate = 220 km / 1.28 Myr ≈ 171.88 km/Myr.
• In cm/yr: 17.188 km/Myr × 100,000 cm/km / 1,000,000 yr ≈ 1.72 cm/yr.

The decrease in the rate—from approximately 5.88 cm/yr in older segments to 1.72 cm/yr in more recent ones—suggests a slowdown in the Pacific Plate’s movement relative to the Hawaiian hotspot. This conclusion is supported by Rubin’s age-distance trend, which shows a diminishing rate over time (Rubin, 2016).

Age-Distance Trend and Predictions

Rubin (2016) illustrates a linear relationship where the distance from the hotspot increases with the age of the island, consistent with steady plate motion. For a newly discovered island at 15 Ma, plotting this against the trend predicts a distance of approximately 870 km from Kilauea. Conversely, an island located 5325 km from Kilauea would be estimated to have an age near 85 Ma, following the linear age-distance model.

Geothermal Energy Potential

The Hawaiian Islands' geothermal potential correlates with volcanic activity and heat flow. The Big Island, being the youngest and most volcanically active, offers the most suitable site for geothermal energy extraction (Wenner & Baer, 2016). Therefore, the most promising location for a geothermal plant is on the Big Island, where high geothermal gradients and accessible volcanic reservoirs exist.

Conclusion

This analysis provides insight into the mechanisms of coastal flooding, the application of hypsometric curves, and the relationship between plate tectonics and island formation in Hawaii. Understanding storm surge factors informs hazard preparedness, while geological data guides sustainable resource utilization. The findings advocate for targeted infrastructure resilience and renewable energy development on the most geothermally active Hawaiian islands.

References

• Eakins, B. W., & Sharman, G. F. (2012). Hypsographic Curve of Earth's Surface from ETOPO1. NOAA National Geophysical Data Center.
• Geggel, L. (2016). Hurricane Matthew: Why Are Storm Surges So Deadly? Live Science.
• NOAA. (2016). Coastal Hypsographic Data and Topographic Elevations. National Oceanic and Atmospheric Administration.
• Rubin, K. (2016). The Formation of the Hawaiian Islands. Hawaii Center for Volcanology.
• Wenner, J. M., & Baer, E. M. (2016). How do I read the hypsometric curve? The Math You Need, When You Need It.
• United States Geological Survey. (2016). The long trail of the Hawaiian hotspot.
• United States Geological Survey. Hawaiian Volcanoes.
• National Hurricane Center. (2016). Storm Surge Overview. NOAA.
• Marshak, S. (2015). Earth: Portrait of a Planet (5th ed.). W.W. Norton.
• Laquatra, J. (2018). Geothermal resource assessment for Hawaii. Journal of Renewable Energy.