ruaumoko: 1990 Rotoaira/Rotopounamu quakes

Friday

1990 Rotoaira/Rotopounamu quakes

There were 14 earthquakes in the Rotoaira/Rotopounamu area in 1990. There were no swarms as such but there were several dates when two micro or very minor quakes hit within less than 5 hrs, notably 29th Oct., 5th Nov., 19th Dec and 23rd Dec. The largest and deepest event of 1990 was a 3.496ML, at 244km deep, located just south of the Wairehu Canal on the western shore of Lake Rotoaira on 8th April at 17:11:00.9 UTC, (marked on map as a purple coloured orb). The 2nd deepest quake was the 3.189ML at 115km deep on 16th February at 03:03:01.6 located between Puketopo and Pukemohono Cones NNE of lake Rotopounamu. (shown on map as a magenta coloured orb). Another deep quake was centred under Mt. Pihanga on 4th March at 23:41:49.1 at a depth of 93km and magnitude of 2.583ML total 14 quakes Rotoaira/Rotopounamu area 1990

total 14 quakes Rotoaira/Rotopounamu area 1990

REF, LAT, LONG, TIME, DEPTH, MAG
98582, -39.01861, 175.75069, 1990/02/16 03:03:01.6, 115, 3.189
112591, -39.0459, 175.75883, 1990/03/04 23:41:49.1, 93, 2.583
119394, -39.03847, 175.68613, 1990/04/08 17:11:00.9, 244, 3.496
170426, -39.05144, 175.66441, 1990/10/29 21:08:45.9, 5, 1.617
170428, -39.03138, 175.66093, 1990/10/29 21:37:14.2, 5, 1.317
170953, -39.02436, 175.70148, 1990/10/31 11:45:30.3, 5, 1.41
171383, -39.03203, 175.72615, 1990/11/05 14:35:46.7, 5, 2.48
172173, -39.02681, 175.67422, 1990/11/05 18:41:32.9, 5, 1.248
177666, -39.03676, 175.68073, 1990/11/25 07:31:47.1, 5, 1.243
188530, -39.02008, 175.77379, 1990/12/19 16:06:26.2, 5, 1.894
182943, -39.02133, 175.77538, 1990/12/19 16:50:26.3, 5, 2.943
182978, -39.02925, 175.78308, 1990/12/21 05:12:29.5, 5, 1.338
188536, -39.01587, 175.76048, 1990/12/23 02:30:32.6, 5, 1.291
188537, -39.02323, 175.76161, 1990/12/23 07:07:32.7, 11, 1.316

data by geonet. map by google maps. plots by highace using GPS Visualizer

No comments:

Post a Comment

Earthquake Swarms

Earthquake swarms are events where a local area experiences sequences of many earthquakes striking in a relatively short period of time. The length of time used to define the swarm itself varies, but the United States Geological Survey points out that an event may be on the order of days, weeks, or months. They are differentiated from earthquakes succeeded by a series of aftershocks by the observation that no single earthquake in the sequence is obviously the main shock. Earthquake swarms are one of the events typically preceding eruptions of volcanoes

Earthquake Aftershocks

An aftershock is an earthquake that occurs after a previous earthquake (the main shock). An aftershock is in the same region of the main shock but is always of smaller magnitude strength. If an aftershock is larger than the main shock, the aftershock is redesignated as the main shock and the original main shock is redesignated as a foreshock. Aftershocks are smaller earthquakes formed as the crust around the displaced fault plane adjusts to the effects of the main shock

Aftershocks are dangerous because they are usually unpredictable, can be of a large magnitude, and can collapse buildings that are damaged from the mainshock. Bigger earthquakes have more and larger aftershocks and the sequences can last for years or even longer especially when a large event occurs in a seismically quiet area; see, for example, the New Madrid Seismic Zone, where events still follow Omori's law from the mainshocks of 1811–1812. An aftershock sequence is deemed to have ended when the rate of seismicity drops back to a background level; i.e., no further decay in the number of events with time can be detected.