Please note: the results below are estimates based on current (limited) understanding of the impact process and come with large uncertainties; they should be used with caution, particularly in the case of peculiar input parameters. All values are given to three significant figures but this does not reflect the precision of the estimate. For more information about the uncertainty associated with our calculations and a full discussion of this program, please refer to this article
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Your Inputs:
- Distance from Impact: 531.00 km ( = 330.00 miles )
- Projectile diameter: 900.00 meters ( = 2950.00 feet )
- Projectile Density: 8000 kg/m3
- Impact Velocity: 51.00 km per second ( = 31.70 miles per second )
- Impact Angle: 45 degrees
- Target Density: 2750 kg/m3
- Target Type: Crystalline Rock
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Energy:
- Energy before atmospheric entry: 3.97 x 1021 Joules = 9.49 x 105 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 4.4 x 106years
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Major Global Changes:
- The Earth is not strongly disturbed by the impact and loses negligible mass.
- The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).
- The impact does not shift the Earth's orbit noticeably.
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Crater Dimensions:
- What does this mean?
- Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.
- Transient Crater Diameter:
21.2 km ( = 13.2 miles )
- Transient Crater Depth: 7.5 km ( = 4.66 miles )
- Final Crater Diameter:
31.7 km ( = 19.7 miles )
- Final Crater Depth: 838 meters ( = 2750 feet )
- The crater formed is a complex crater.
- The volume of the target melted or vaporized is 24.9 km3 = 5.97 miles3
- Roughly half the melt remains in the crater, where its average thickness is 70.4 meters ( = 231 feet ).
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Thermal Radiation:
- What does this mean?
- Time for maximum radiation: 622 milliseconds after impact
- Visible fireball radius: 9.48 km ( = 5.88 miles )
- The fireball appears 4.05 times larger than the sun
- Thermal Exposure: 1.26 x 106 Joules/m2
- Duration of Irradiation: 6.85 minutes
- Radiant flux (relative to the sun): 3.06
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Seismic Effects:
- What does this mean?
The major seismic shaking will arrive approximately 1.77 minutes after impact.- Richter Scale Magnitude: 8.6
- Mercalli Scale Intensity at a distance of 531.3 km:
IV. Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows, doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing motor cars rocked noticeably.
V. Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned. Pendulum clocks may stop.
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Ejecta:
- What does this mean?
The ejecta will arrive approximately 5.76 minutes after the impact.- At your position there is a fine dusting of ejecta with occasional larger fragments
- Average Ejecta Thickness: 1.2 cm ( = 0.474 inches )
- Mean Fragment Diameter: 2.48 mm ( = 0.977 tenths of an inch )
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Air Blast:
- What does this mean?
The air blast will arrive approximately 26.8 minutes after impact.- Peak Overpressure: 23400 Pa = 0.234 bars = 3.32 psi
- Max wind velocity: 50.4 m/s = 113 mph
- Sound Intensity: 87 dB (Loud as heavy traffic)
- Damage Description:
Interior partitions of wood frame buildings will be blown down. Roof will be severely damaged.
Glass windows will shatter.
About 30 percent of trees blown down; remainder have some branches and leaves blown off.
Tell me more...
Click here for a pdf document that details the observations, assumptions, and equations upon which this program is based. It
describes our approach to quantifying the important impact processes that might affect the people, buildings, and landscape in the
vicinity of an impact event and discusses the uncertainty in our predictions. The processes included are: atmospheric entry, impact
crater formation, fireball expansion and thermal radiation, ejecta deposition, seismic shaking, and the propagation of the atmospheric
blast wave.
Recent improvements in the airblast calculation are described here.
Earth Impact Effects Program Copyright 2004, Robert Marcus, H.J. Melosh, and G.S. Collins
These results come with ABSOLUTELY NO WARRANTY