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: 4830.00 km ( = 3000.00 miles )
- Projectile diameter: 11.30 km ( = 7.00 miles )
- Projectile Density: 3000 kg/m3
- Impact Velocity: 20.00 km per second ( = 12.40 miles per second )
- Impact Angle: 60 degrees
- Target Density: 2750 kg/m3
- Target Type: Crystalline Rock
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Energy:
- Energy before atmospheric entry: 4.49 x 1023 Joules = 1.07 x 108 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.7 x 108years
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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).
- Depending on the direction and location of impact, the collision may cause a change in the length of the day of up to 1.75 milliseconds.
- The impact does not shift the Earth's orbit noticeably.
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Crater Dimensions:
- What does this mean?
- Transient Crater Diameter:
77.9 km ( = 48.4 miles )
- Transient Crater Depth: 27.5 km ( = 17.1 miles )
- Final Crater Diameter:
138 km ( = 85.7 miles )
- Final Crater Depth: 1.3 km ( = 0.81 miles )
- The crater formed is a complex crater.
- The volume of the target melted or vaporized is 3460 km3 = 830 miles3
- Roughly half the melt remains in the crater, where its average thickness is 726 meters ( = 2380 feet ).
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Thermal Radiation:
- What does this mean?
- The fireball is below the horizon. There is no direct thermal radiation.
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Seismic Effects:
- What does this mean?
The major seismic shaking will arrive approximately 16.1 minutes after impact.- Richter Scale Magnitude: 10.0 (This is greater than any earthquake in recorded history)
- Mercalli Scale Intensity at a distance of 4830 km:
III. Felt quite noticeably by persons indoors, especially on upper floors of buildings. Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck.
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.
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Ejecta:
- What does this mean?
The ejecta will arrive approximately 25.4 minutes after the impact.- At your position there is a fine dusting of ejecta with occasional larger fragments
- Average Ejecta Thickness: 2.91 mm ( = 1.15 tenths of an inch )
- Mean Fragment Diameter: 32.5 microns ( = 1.28 thousandths of an inch )
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Air Blast:
- What does this mean?
The air blast will arrive approximately 4.07 hours after impact.- Peak Overpressure: 8490 Pa = 0.0849 bars = 1.21 psi
- Max wind velocity: 19.3 m/s = 43.2 mph
- Sound Intensity: 79 dB (Loud as heavy traffic)
- Damage Description:
Glass windows will shatter.
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