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: 37.00 km ( = 23.00 miles )
- Projectile diameter: 370.00 meters ( = 1210.00 feet )
- Projectile Density: 8000 kg/m3
- Impact Velocity: 25.00 km per second ( = 15.50 miles per second )
- Impact Angle: 90 degrees
- Target Density: 1000 kg/m3
- Target Type: Liquid water of depth 14.0 meters ( = 45.9 feet ), over crystalline rock.
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Energy:
- Energy before atmospheric entry: 6.63 x 1019 Joules = 1.58 x 104 MegaTons TNT
- The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.9 x 105years
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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 20400 meters = 66800 ft
- The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 24.9 km/s = 15.5 miles/s
- The energy lost in the atmosphere is 5.86 x 1017 Joules = 1.40 x 102 MegaTons.
- The impact energy is 6.57 x 1019 Joules = 1.57 x 104MegaTons.
- 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 0.412 km by 0.412 km
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Crater Dimensions:
- What does this mean?
- The crater opened in the water has a diameter of 14.3 km ( = 8.88 miles ).
- For the crater formed in the seafloor:
- Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.
- Transient Crater Diameter:
8.72 km ( = 5.41 miles )
- Transient Crater Depth: 3.08 km ( = 1.91 miles )
- Final Crater Diameter:
11.6 km ( = 7.21 miles )
- Final Crater Depth: 619 meters ( = 2030 feet )
- The crater formed is a complex crater.
- The volume of the target melted or vaporized is 0.578 km3 = 0.139 miles3
- Roughly half the melt remains in the crater, where its average thickness is 9.68 meters ( = 31.7 feet ).
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Thermal Radiation:
- What does this mean?
- Time for maximum radiation: 324 milliseconds after impact
- Visible fireball radius: 7.96 km ( = 4.95 miles )
- The fireball appears 48.9 times larger than the sun
- Thermal Exposure: 2.25 x 107 Joules/m2
- Duration of Irradiation: 1.75 minutes
- Radiant flux (relative to the sun): 215
- Effects of Thermal Radiation:
Clothing ignites
Much of the body suffers third degree burns
Newspaper ignites
Plywood flames
Deciduous trees ignite
Grass ignites
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Seismic Effects:
- What does this mean?
The major seismic shaking will arrive approximately 7.4 seconds after impact.- Richter Scale Magnitude: 7.4
- Mercalli Scale Intensity at a distance of 37 km:
IX. General panic. Damage considerable in specially designed structures; well-designed frame structures thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off foundations. Serious damage to reservoirs. Underground pipes broken. Conspicuous cracks in ground. In alluviated areas sand and mud ejected, earthquake fountains, sand craters.
X. Most masonry and frame structures destroyed with their foundations. Some well-built wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large landslides. Water thrown on banks of canals, rivers, lakes, etc. Sand and mud shifted horizontally on beaches and flat land. Rails bent slightly.
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Ejecta:
- What does this mean?
The ejecta will arrive approximately 1.45 minutes after the impact.- At your position there is a fine dusting of ejecta with occasional larger fragments
- Average Ejecta Thickness: 1.02 meters ( = 3.34 feet )
- Mean Fragment Diameter: 1.03 meters ( = 3.37 feet )
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Air Blast:
- What does this mean?
The air blast will arrive approximately 1.87 minutes after impact.- Peak Overpressure: 302000 Pa = 3.02 bars = 42.9 psi
- Max wind velocity: 376 m/s = 841 mph
- Sound Intensity: 110 dB (May cause ear pain)
- Damage Description:
Multistory wall-bearing buildings will collapse.
Wood frame buildings will almost completely collapse.
Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.
Highway truss bridges will collapse.
Glass windows will shatter.
Cars and trucks will be overturned and displaced, requiring major repairs.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.
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Tsunami Wave:
- What does this mean?
- The impact-generated tsunami wave arrives approximately 52.6 minutes after impact.
- Tsunami wave amplitude is between: 2.7 meters ( = 8.9 feet) and 5.4 meters ( = 17.7 feet).
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