Executive Summary.

1. Introduction.

2. Project Description.

2.1 Program Research And Development.
2.1.1 Phase 1 Pre-Collision.
2.1.2 Phase 2 Collision.
2.1.3 Phase 3 Post-Collision.

2.2 Program Synthesis.

4. Conclusions.

5. Recommendations.

6. Acknowledgements.

7. Reference List.

Appendix A - Simulation Results.

Appendix B - Programming Flowcharts.

Appendix C - Computer Program Source Code.

Appendix D - Detailed Models.
 

Introduction. This project explores the effects of a huge meteor hitting the Pacific Ocean. I predicted that the meteor impact would create a huge tsunami which would destroy coastal cities and islands.
When this project began, the effort was split into three parts.This made it easier to see what needed to be researched, organized, and programmed. The phases were:
 
Phase 1 Pre-Collision - The meteor enters the Earth's atmosphere and impacts in the Pacific Ocean.
Phase 2 Collision - The surface wave created on impact travels to the shore.
Phase 3 Post-Collision - A tsunami is formed and surges ashore toward the city.


Mathematical models to describe each phase were identified and developed. These models are described in detail in Appendix D and were programmed into our C program.

Programming. The complete computer program integrated an input routine and routines to model each project phase. Meteor and location parameters were entered through the input routine. The Phase 1, Phase 2, and Phase 3 routines were performed to provide the impact kinetic energy, the maximum tsunami surge inland, and the flood depth in the city as outputs.

Results. A total of 480 scenarios were designed and tested by varying meteor and location parameters. This produced tsunami data for 5 cities of interest (Los Angeles, CA; Tokyo, Japan; San Francisco, CA; Seattle, WA; and Honolulu, HI) which is reported in Appendix A.
None of the tsunamis hit Tokyo or Seattle. Tokyo and Seattle are both over 80 km away from the shore. Honolulu, San Francisco, and Los Angeles were all struck very hard by some tsunamis. These three cities are all less than 10 km from the shore.
The results show that as the location of impact got closer to the shore location, the higher the tsunami would be in the city. As the radius, velocity, and density of the meteor became larger, so did the wave height in the city. As the distance between the shore and the city grew, the wave height in the city became smaller.
Conclusions. Under otherwise constant conditions, as density, radius, and velocity of the meteor rise, the tsunami gets bigger . As either the distance from impact to shore or from shore to city increases, the height of the tsunami in the city decreases. This again assumes that all other parameters are constant.

The ocean depth has a significant effect on the size of a tsunami. Deep water impacts produce larger tsunamis than shallow water impacts.

Coastal features can provide protection from tsunamis. If a city is over 80 km away from the coast, the tsunamis modeled did not produce any effects. When a city is less than 10 km from the shore, tsunamis can cause serious effects. Cities located in the middle of the Pacific are more likely to get hit by a massive tsunami than those stationed on the shores of continents. (This is because the impact site can be no farther than half of the Pacific away. )

Recommendations. Meteor impacts in the Western Pacific should be simulated. In the results of this project, Tokyo was never hit largely because none of the meteors landed anywhere near the city.
The simulation could be improved with a better atmospheric friction model and a better tsunami runup model. Our model for atmospheric friction was very simple and could be improved significantly. The height of the tsunami in the cities would be more accurate using a tsunami runup database model similar to the Etopo5 ocean depth model.

Meteor impacts in other oceans could be investigated. The tsunamis produced in the Indian Ocean may be different than those produced in the Pacific Ocean and the effects on the cities could also change.

Finally, I'd like to recommend that the height of the tsunami be interpreted in terms of dollar damage and lives lost. This would be an impressive and meaningful demonstration of the impact of a meteor-induced tsunami.

1. Introduction. This project is entitled: What are the effects of a huge meteor hitting the Earth in the Pacific Ocean? The movie Armageddon inspired this project. The movie is about a huge meteor that is on a collision course with Earth. The prediction of the meteor causing the end of the world was interesting. Unfortunately, it did not really explain in detail what would happen if the meteor hit the Earth in one of its oceans.

That lead to this project. The only prediction that seems logical to me is that the meteor would generate a tsunami that would destroy coastal cities.

2. Project description. This project modeled the collision of a huge meteor hitting the Earth in the Pacific Ocean. The energy of the meteor was transferred into a surface wave which produced a tsunami that flooded a nearby coastal city. The flood depth in the city and the maximum flood surge inland were predicted by the computer program developed.

2.1 Program Research and Development. During this project, it became desirable to split the project into three phases. Splitting up this project into three phases helped clear up exactly what had to be done for each part of the project. It also helped make programming easier in that the program could be split up, making it easier to see what was missing or wrong in the program. The following phases seemed to be the natural phases of the project:

Phase 1 Pre-collision,
Phase 2 Collision, and
Phase 3 Post-Collision.

2.1.1 Phase 1 Pre-collision. In phase 1, pre-collision, or before collision, the scenario starts with a meteor heading toward the Earth. The meteor then enters the atmosphere where some of the kinetic energy is absorbed. The meteor then hits the ocean where the remaining kinetic energy of the meteor is transferred to the ocean. This collision is modeled as a total inelastic collision (a collision in which the two masses don't rebound) in which all the kinetic energy of the meteor is transferred into the ocean at impact, completing phase 1.

2.1.1.1 Simulation and Modeling. For phase 1, a lot of research had to be done. Five models were needed to simulate the meteor entering the atmosphere and colliding with the ocean. The models needed included:
 

Model	Equation	Details
Meteor Volume (m3)		Section D.1.1, page D-1
Meteor Mass (kg)		Section D.1.2, page D-1
Meteor Initial Kinetic Energy (joules)		Section D.1.3, page D-1
Atmospheric Energy Losses (joules)		Section D.1.4, page D-2
Inelastic Collision (Gigatons)		Section D.1.5, page D-2

These models are completely described in section D.1 of Appendix D Detailed Models.

2.1.1.2 Programming. The previously described models were coded into the Phase 1 routine in the computer program. This routine was written in C and required the meteor radius, velocity, and density as inputs. A flowchart describing the Phase 1 code is shown in Figure B-1 on page B-1 of Appendix B.

First, the program computes the volume of a sphere using the meteor radius. Then, the volume and the density of the meteor are combined to model the meteor's mass.

The initial kinetic energy of the meteor is then modeled by combining the mass and velocity of the meteor. We then apply the atmospheric energy loss model to the initial kinetic energy to determine the kinetic energy of the meteor at impact. Finally, the inelastic collision model is applied to determine the kinetic energy transferred to the ocean at impact. This result is used as the input for Phase 2.
The computer code for Phase 1 is presented in appendix C on page C-9.

2.1.2 Phase 2 Collision. The next phase is phase 2, the phase where the collision actually happens. In this phase, the kinetic energy transferred to the ocean from Phase 1 is used to model a surface wave that propagates until reaching the shoreline.

2.1.2.1 Research and Development. There were 4 models needed to complete this phase. These models are as follow:
 

Model	Equation	Details
Distance From The Impact Site To The Shore (km)	Haversine Model	Section D.2.1, page D-2
Ocean Depth (m)	Etopo5 Model	Section D.2.2, page D-3
Wave Propagation (m), deep water impact		Section D.2.3, page D-3
Wave Propagation (m), shallow water impact		Section D.2.3, page D-3
Peak amplitude of surface wave (m)		Section D.2.4, page D-3

These models are completely described in section D.2 of Appendix D Detailed Models.

2.1.2.2 Programming. The previously described models were coded into the Phase 2 routine in the computer program. This routine required the kinetic energy transferred to the ocean from Phase 1, the impact location longitude and latitude, and the shoreline latitude and longitude as inputs. A flowchart describing the Phase 2 code is shown in Figure B-2 on page B-2 of Appendix B.

The depth of the ocean at the impact site was found using the impact latitude and longitude to select the appropriate ocean depth from the Etopo5 database. The impact longitude and latitude was also combined with the shoreline latitude and longitude to find the distance from the impact site to the shore using the Haversine model for distance from point-to-point on a globe.

The depth of the ocean, the distance from the impact site to the shore, and the impact kinetic energy from phase 1 are all applied to the wave propagation model to find the peak-to-peak amplitude of the surface wave at the shore. The peak amplitude of the surface wave is finally computed and is the output of phase 2.

The code for this phase is in Appendix C on pages C-10 through C-11.

2.1.3 Phase 3 Post-Collision. Phase 3 starts with the surface wave at the shore. When the surface wave gets into shallow water, it builds up height and turns into a tsunami. The tsunami then surges inland toward the city. The flood depth of the tsunami and the maximum surge inland were modeled.

2.1.3.1 Research and Development. There were 4 models required to complete this phase. They are:

Model	Equation	Details
Shoreline depth (m)		Section D.3.1, page D-4
Maximum Tsunami Surge Inland (km)		Section D.3.2, page D-4
Distance between shore and city (km)	Haversine Model	Section D.3.3, page D-4
Flood depth in city (m)		Section D.3.4, page D-5

These models are completely described in section D.3 of Appendix D Detailed Models.

2.1.3.2 Phase 3 Programming. The previously described models were coded into the Phase 3 routine in the computer program. This routine required the peak amplitude of the surface wave modeled in Phase 2, the shoreline latitude and longitude, and the city latitude and longitude as inputs. A flowchart describing the Phase 3 code is shown in Figure B-3 on page B-3 of Appendix B.

The peak amplitude from phase two was applied to the tsunami runup to determine the shoreline height of the tsunami. The tsunami height at the shore was then used to determine the maximum tsunami surge inland. The shoreline longitude and latitude were combined with the city latitude and longitude to find the distance from the shore to the city using the Haversine model.
The distance from the shore to the city, the maximum tsunami surge inland, and the tsunami height at the shore are all used to determine the flood depth in the city. Phase 3 outputs are the maximum tsunami surge inland and the flood depth in the city.
The code for this phase is in Appendix C on pages C-12 through C-13.

2.2 Program Synthesis. Figure 1 presents a flowchart of the complete computer program integrating the three program phases with an input routine. Meteor and location parameters were entered through the input routine. The Phase 1, Phase 2, and Phase 3 routines were performed to provide the impact kinetic energy, the maximum tsunami surge inland, and the flood depth in the city as outputs.

The code for the input routine and the main program is in Appendix C on pages C-1 through C-3 and pages C-4 through C-8, respectively.
Test scenarios were selected by choosing combinations of city and meteor parameters. Five cities, 4 impact locations, 3 meteor densities, 3 meteor radii, and 3 meteor velocities were selected. The following tables display the values selected:

3. Results. By combining the values in Tables 1 and 2, a total of 480 scenarios were designed and tested. These tests produce a very large number of results which are reported in Appendix A.

Table 3 presents a sample of the results from 5 scenarios. In these scenarios, a 200-meter iron-nickel meteor impacted the Pacific Ocean. Los Angeles, Tokyo, and Seattle were not hit by the tsunami created by the impact. All three cities lie some distance off the shore which makes the tsunami get smaller before it hits the city. The maximum flood surge is less than the distance of the city from the shore.
San Francisco and Honolulu, however, had very large tsunamis hit them. These cities are nearly on the shore and the tsunami does not shrink much before reaching the city.

In the results in Appendix A, none of the tsunamis hit Tokyo or Seattle. Tokyo and Seattle are both over 80 km away from the shore. Honolulu, San Francisco, and Los Angeles were all struck very hard by some tsunamis. These three cities are all less then 10 km from the shore.
The results show that as the location of impact got closer to the shore location, the higher the tsunami would be in the city. As the radius, velocity, and density of the meteor became larger, so did the wave height in the city. As the distance between the shore and the city increased, the wave height in the city became smaller.

4. Conclusions. Under otherwise constant conditions, as the density, radius, and velocity of the meteor rise, the tsunami gets bigger. This was easily predictable, as the models show that as these parameters increase, so did the kinetic energy and subsequently the height of the tsunami.
As either the distance from impact to shore or from shore to city increases, the height of the tsunami in the city decreases. This again assumes that all other parameters are constant.

The ocean depth has a significant effect on the size of a tsunami. Deep water impacts produce larger tsunamis than shallow water impacts.

Coastal features can provide protection from tsunamis. If a city is over 80 km away from the coast, the tsunamis modeled did not produce any effects. When a city is less than 10 km from the shore, tsunamis can cause serious effects.

Cities located in the middle of the Pacific are more likely to get hit by a massive tsunami than those stationed on the shores of continents. This is because the impact site can be no farther than half of the Pacific away.

5. Recommendations. Meteor impacts in the Western Pacific should be simulated. In the results of this test, Tokyo was never hit partially because none of the meteors landed anywhere near the city.

The simulation could be improved with a better atmospheric friction models. Our model for atmospheric friction was very simple and could be improved significantly.

The simulation could be improved with a better tsunami runup model. The height of the tsunami in the cities would be more accurate using a tsunami runup database model similar to the Etopo5 ocean depth model.

Meteor impacts in other oceans could be investigated. The tsunamis produced in the Indian Ocean may be different than those produced in the Pacific Ocean and the effects on the cities could also change.

Finally, I'd like to recommend that the height of the tsunami be interpreted in terms of dollar damage and lives lost. This would be a impressive and meaningful demonstration of the impact of a meteor-induced tsunami.

6. Acknowledgments. I would like to thank many people who helped me while I was doing this project. I would like to thank Ms. Suzukida, Mr. Simon, and Mrs. Tinguely for introducing me to this activity and helping me get some of the research that I needed. I would like to thank my mentor, Reese Sturdevant, for helping me throughout this project and urging me on. I would like to thank the SCC and the scientists working with the SCC for helping me find materials and introducing me to programming. I would also like to thank Mr. John Feist for going to NMSU in Las Cruses to retrieve research information that was located there.

7. Reference List
 

1. http://library.advanced.org/16600/
2. Holmes, Harrison, Explosives, Encyclopedia Americana Grolier Incorporated, Volume 10, page 791, (1994).
3. Kochan, Stephen G., Programming in C, Revised Edition, (Hayden Books, Indianapolis, 1988).
4. Prado, Mark, Asteroids - Effects of an Impact on Earth[On-line]. (1997) Available: http://www.permanent.com/a_impact.htm.
5. Weast, Robert H., CRC Handbook of Chemistry and Physics, College Edition, (The Chemical Rubber Publishing Co., 1962)
6. Information about the Etopo5 5-Minute Gridded Elevation Data[Online]. (1999) Available: http://www.ngdc.noaa.gov/mgg/global/etopo5.html, (NOAA National Data Center.)
7. Hills, Jack G. and Mader, Charles L., "Tsunamis Produced by the Impact of Small Asteroids," Proceedings of the Planetary Defence Workshop Lawrence Livermore National Laboratory, (May 1995)
8. Documentation for 'ETOPO-5' Data Set"[On-line]. (1998) Available:
http://grid2.cr.usgs.gov/data/etopo5.elev.html,(UNEP/GRID, Sioux Falls.
9. Arnett, Bill, Meteors, Meteorites & Impacts,[On-line]. (1998)
http://sedds.lpl.arizona.edu/nineplanets/nineplanets/meteorites.html.
10. Beyer, William H., CRC Handbook of Mathematical Sciences, 5th Edition, (CRC Press,
1980).
11. Chien, Chao C., Programmer's Guide to Turbo C2, (Bantam Books, New York, 1989).
12 . Eshback, Ovid W., Handbook of Engineering Fundamentals, 3rd Edition, (John Wiley & Sons, 1975).
13. Kochan, Stephen G., Programming In C, Revised Edition, (Hayden Books, Indianapolis, 1988). 14. Weast, Robert H., CRC Handbook of Chemistry and Physics, College Edition, (The Chemical Rubber Publishing Co., 1962).