Using ultra-long period records of the 1977 Indonesian earthquake from seven IDA stations, we have measured the attenuation of fundamental spheroidal modes from 0S6 to 0S28. We determine the attenuation of each mode using a time domain technique which minimizes the effects of noise on the measurements. These measurements are the first attenuation data for these modes from multiple ultra-long period records of a single earthquake. Our results are in good general agreement with single station attenuation measurements from the UCLA gravimeter records of the Alaskan earthquake. They show systematically lower Q−1(less attenuation) than results from stacking WWSSN records.

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