The Letter Series and the Golden Years of IH. The F-series tractors lasted until 1939. In late 1939, the famous Letter series of Farmall tractors was introduced. The model name letters were A, B, BN, C (which replaced the B and BN in 1948), H, M, and MD(M diesel).
Japan has had a long history of earthquakes and seismic activity. It is an area of high seismicity because it is located near major tectonic plate boundaries and is situated on the Pacific Ring of Fire.n July 16, 2007, an earthquake measuring 6.6 M, the 2007 ChÅ«etsu offshore earthquake hit about 29 kilometres (18 mi) west of Niigata in the northwest Niigata region of Japan. ) was a powerful magnitude 6.6 earthquake The earthquake shook Niigata and neighbouring prefectures.
BY Jenny Marder March 11, 2011 at 1:47 PM EDT. The 8.9-magnitude earthquake that struck coastal Japan on Friday, devastating large swaths of the coast and spawning a powerful tsunami, was caused by the Pacific tectonic plate thrusting underneath the country, and forcing the seabed and ocean water upward.isplacement of the fault by a magnitude 7.2 earthquake two days ago triggered aftershocks, including, in this case, the big earthquake. And since this morningâs quake, the area has had 100 magnitude 5 aftershocks, nearly 20 magnitude-6 aftershocks and one magnitude 7 aftershock.