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: 10.00 km ( = 6.21 miles )
- Projectile diameter: 140.00 meters ( = 459.00 feet )
- Projectile Density: 1500 kg/m3
- Impact Velocity: 17.00 km per second ( = 10.60 miles per second )
- Impact Angle: 45 degrees
- Target Density: 2500 kg/m3
- Target Type: Sedimentary Rock
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Energy:
- Energy before atmospheric entry: 3.11 x 1017 Joules = 7.44 x 101 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 8.0 x 103years
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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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Atmospheric Entry:
- The projectile begins to breakup at an altitude of 72500 meters = 238000 ft
- The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 4 km/s = 2.48 miles/s
- The energy lost in the atmosphere is 2.94 x 1017 Joules = 7.03 x 101 MegaTons.
- The impact energy is 1.72 x 1016 Joules = 4.11 MegaTons.
- The larger of these two energies is used to estimate the airblast damage.
- The broken projectile fragments strike the ground in an ellipse of dimension 1.17 km by 0.829 km
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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:
958 meters ( = 3140 feet )
- Transient Crater Depth: 339 meters ( = 1110 feet )
- Final Crater Diameter:
1.2 km ( = 0.744 miles )
- Final Crater Depth: 255 meters ( = 836 feet )
- The crater formed is a simple crater
- The floor of the crater is underlain by a lens of broken rock debris (breccia) with a maximum thickness of 118 meters ( = 388 feet ).
- At this impact velocity ( < 12 km/s), little shock melting of the target occurs.
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Thermal Radiation:
- What does this mean?
- At this impact velocity ( < 15 km/s), little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.
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Seismic Effects:
- What does this mean?
The major seismic shaking will arrive approximately 2 seconds after impact.- Richter Scale Magnitude: 5.0
- Mercalli Scale Intensity at a distance of 10 km:
VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.
VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.
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Ejecta:
- What does this mean?
- Most ejecta is blocked by Earth's atmosphere
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Air Blast:
- What does this mean?
The air blast will arrive approximately 30.3 seconds after impact.- Peak Overpressure: 107000 Pa = 1.07 bars = 15.3 psi
- Max wind velocity: 183 m/s = 409 mph
- Sound Intensity: 101 dB (May cause ear pain)
- Damage Description:
Multistory wall-bearing buildings will collapse.
Wood frame buildings will almost completely collapse.
Highway truss bridges will suffer substantial distortion of bracing.
Glass windows will shatter.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.
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