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Provisions for Earthquake |
Seeing recent disaster in Niigata Pref., Mr. Greenwood studied various provisions for possible earthquake.
Probability of plate type earthquake around Kamakura
| Name of Plate | Magnitude | Probability within 30years (%) |
| Sagami Trough | 7.9 | 0.8 |
| Toukai Plate | 8 | 87 |
Probability of falt type earthquake around Kamakura
According to government, probability and magnitude of possible earthquake caused by faults around Kamakura are listed as in the following table.
| Name of the Faults | Seismic Intensity | Probability within 30years (%) |
| Faults in Miura Peninsula | 6.5（Takayama） 6.7（Kinugawa/Kitatake） 6.0（Hikibashi） | >3 |
| Isehara Faults | 7.9 | <0.1 |
| Kaminawa/Kouzu-Matsuda Faults | 8.0 | >3 |
The location of the faults are shown in the following map.
Major faults around Kamakura
Seismic Intensity of the possible cause
| Name of the Cause i.e. Plate & Faults | Magnitude | Depth of The Center (km) | Horizontal Distance (km) | True Distance (km) | Seismic Intensity | Acceleration （gal） |
| Toukai Plate | 8 | 15 | 145 | 146 | 4.7 | 159 |
| Faults in Miura Peninsula | 6.7 | 10 | 10 | 14 | 5.6 | 479 |
| Kaminawa/Kouzu-Matsuda Faults | 8 | 10 | 28 | 30 | 6.1 | 963 |
Protecting structure of House
＜Movement of Foundation＞
As a house of Mr. Greenwood is standing at the edge of a rock facing the Sagami Bay, expected acceleration by earthquake would be 400gal. As 1gal=1cm/sec2 and acceleration of gravity is 9.8m/sec2 Horizontal force would be 0.41G. Velocity of the movement would be 40kine which is equal to 40cm/sec.
＜Spec of the house＞
The house was build in traditional wooden frame structure in 1979. He minimized window openings and added cross bracings in all walls. But due to weight of books in his library he is not satisfied.
 Cross bracing 1 photo 2010/6/15 |
 Cross bracing 2 photo 2010/6/15 |
＜Addition of oil damper＞
He had made a quick study of adding oil damper to his house in the intent to convert earthquake energy into heat. An oil damper having the capability to move at the speed of 40cm/sec with 800kg force will absorb 10% of the energy.
Damper for earthquake
Fixing Furniture
 L shape metal |
 H shape metal |
Provisions for survival over a week after the loss of social infrastructure
＜Stock outside house and garage＞
*Camping tent, mat and cooking utensils
*Potable water 20 liter
*Canned food
*Solar powered FM/AM radio plus LED flash light and fluorescent lamp.
*Emergency gasoline engine generator of 60Hz, 850W output and 18 liter gasoline and 360cc lube oil for 24 hr continuous operation.
Emergency Gasoline Engine Generator
*Tools for recovery of household from the fallen house
＜Stock in a boat＞
Keeping Canned food in ROCA might be a good backup.
Insurance for earthquake
Insurance is the only provisions for rebuilding.
November 28, 2004
Rev. June 15, 2010