Geophysics and Seismology Commons^™

Final Report: Task 22 — Extreme Ground Motion Studies, John G. Anderson, James N. Brune, Jaak J.K. Daemen, Matthew Purvance

Publications (YM)

TASK 22 consisted of two separate investigations into extreme ground motions due to seismic events, Subtask 1 and Subtask 2. Subtask 1 included field studies of geological formations that should put an upper bound on extreme ground motions that have happened at the site of the formations. The locations are critically selected to provide the most effective constraints possible on the validity of the probabilistic seismic hazard analysis for Yucca Mountain. Subtask 2 surveyed recorded ground motions from around the world, with the aim to draw general conclusions from these as to the conditions where extreme ground motions are observed. …

Exceptional Ground Accelerations And Velocities Caused By Earthquakes, John G. Anderson, James N. Brune

Publications (YM)

This project aims to understand the characteristics of the free-field strong-motion records that have yielded the 100 largest peak accelerations and the 100 largest peak velocities recorded to date. The peak is defined as the maximum magnitude of the acceleration or velocity vector during the strong shaking. This compilation includes 35 records with peak acceleration greater than gravity, and 41 records with peak velocities greater than 100 cm/s. The results represent an estimated 150,000 instrument-years of strong-motion recordings. The mean horizontal acceleration or velocity, as used for the NGA ground motion models, is typically 0.76 times the magnitude of this …

Seismicity In The Vicinity Of Yucca Mountain, Nevada, For The Period October 1, 2002 To September 30, 2003, Ken Smith, David Vin Seggern, John G. Anderson, Richard Quittmeyer, Amy J. Smiecinski

Publications (YM)

Earthquake activity in the Yucca Mountain from October 1, 2002 through September 30, 2003 (FY03) is assessed and compared with previous activity in the region. FY03 is the first reporting year since the 1992 M 5.6 Little Skull Mountain earthquake with no earthquakes greater than M 3.0 within 65 km of Yucca Mountain. In addition, FY03 includes the fewest number of earthquakes greater than M 2.0 in any reporting year since the LSM event. With 3075 earthquakes in the catalog, FY03 represents the second largest number of earthquakes (second to FY02) since FY96 when digital seismic network operations began. The …

Seismicity In The Vicinity Of Yucca Mountain, Nevada, For The Period October 1, 2003, To September 30, 2004, David Von Seggern, Ken Smith, John G. Anderson, Amy J. Smiecinski

Publications (YM)

This report describes the seismicity and earthquake monitoring activities within the Yucca Mountain region during fiscal year 2004 (FY2004 - October 1, 2003, through September 30, 2004) based on operation of the Southern Great Basin Digital Seismic Network (SGBDSN). Network practices and earthquake monitoring conducted at the Nevada Seismological Laboratory (NSL) under DOE directives for prior fiscal years are covered in similar yearly reports (see references). Real-time systems, including regional data telemetry and data management at NSL, provide for the automatic determination of earthquake locations and magnitudes and notification of important earthquakes in the region to UNR staff and DOE …

Extreme Ground Motion Studies, James N. Brune, John G. Anderson

Publications (YM)

Subtasks:

1. Constraints on Yucca Mountain extreme ground motion based on precariously balanced rocks, unstable precipitous cliffs, and un-fractured sandstone along the San Andreas fault.

2. Prepare summary report on large recorded ground motions.

Geodetic Monitoring Of The Yucca Mountain Region Using Continuous Gps Measurements, Geoff Blewitt, Jonathan Price, Nevada Geodetic Laboratory, Nevada Bureau Of Mines & Geology

Publications (YM)

What Task 3 is About: Monitor current crustal deformation at YM
– In the broader tectonic context of the NA-Pacific plate boundary
– In the regional context of the East California Shear Zone (ECSZ)
– In the geological context of specific fault activity
– Vertical motion associated with geophysical fluids

Using geodetic methods
– GPS – mature, proven
track the 3-D point-positions of 47 stations with < 1 mm precision
– InSAR – new, experimental
regional map of displacement along the line-of-sight (accuracy??)
proven capability: (1) co-seismic deformation; (2) local instabilities

Longbase Laser Strainmeter Measurements At Yucca Mountain, James N. Brune

Publications (YM)

Why Operate a Strainmeter? To monitor strain over a broader bandwidth and with much higher sensitivity than GPS (or other instruments):
– Measure strain from seismic, earth-tide, temperature and air pressure inputs--gives local rock properties, and changes in them.
– Independently constrains GPS results.

To directly measure in the Yucca Mountain Block:
– Sensitive to potential very local tectonic events, (including any triggered slip), or volcanic events.

To establish a baseline for future strain changes:
– E.g., events developing from loading and heating of the repository

A Geodetic Investigation Of Ground Deformation At Yucca Mountain, Southern Nevada, Emma Mccaughey

Publications (YM)

The data from 28 continuous BARGEN GPS stations in the Yucca Mountain region were processed for January 2000 to June 2004. The data have been processed independently using both the GIPSY and GAMIT software packages for quality assurance purposes, yielding an RMS of velocity differences between the solutions of 0.06 mm/yr for the east and 0.10 mm/yr for the north. The velocity solution for the local Yucca Mountain network has a relatively smooth signal showing NW-trending rightlateral shear. The magnitude of the velocity contrast across the local network, from east to west, is 0.95 ± 0.04 mm/yr. The GPS results …

Time Dependent Mechanical Behavior Of Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

This part of the Technical Report includes four types of experimental studies: strain rate dependence, uniaxial creep, Brazilian (Indirect splitting) tensile strength and uniaxial compressive strength. These are presented in four chapters. One hundred twenty one specimens have been tested in uniaxial compression. Ninety three of these are included in the strain rate dependence study, presented in Chapter 2. Uniaxial compression strain rates range from about 10~8 to 10~2 s~l. Results of twenty eight tests are presented in Chapter 5, which describes uniaxial compression testing of specimens containing major lithophysal cavities. Fourteen specimens have been tested in uniaxial creep, presented …

Experimental Determination Of Stiffness Of Joints In Welded Tuff, Jaak J.K. Daemen, George Danko, Amy J. Smiecinski

Publications (YM)

Fourteen uniaxial joint compression tests were run to determine the normal and shear stiffnesses of type 1 fracture joints (healed joints filled with vapor-phase mineral deposits) obtained from the Yucca Mountain site. The uniaxial joint compression results show that these joints behave linearly up to over 85% of their loading history. They are stiff with strengths very close to the strength of the intact rock. Five direct shear tests were run on open, separated, joints. Results obtained from the direct shear testing show that the normal stiffness increases with increasing normal stress. Shearing through asperities gives high joint shear stiffness …

Final Report On Task 12: Southern Great Basin Seismic Network Operations, James N. Brune, David Von Seggern, Ken Smith, Glenn Biasi

Publications (YM)

The Nevada Seismological Laboratory began seismic monitoring operations under the DOE-UCCSN Cooperative Agreement on 11/01/1999. This final report summarizes our activities and studies made in the four years up to 09/30/2003. Previously, NSL operated under the M&O for the Yucca Mountain Project from October 1995 through September 1999 and under the U. S. Geological Survey from October 1992 through September 1995. For purposes of this report, earthquakes occurring in the years FY1998 and FY1999 were analyzed in the first two years of the NSL’s involvement with the Cooperative Agreement, and they will be treated here, along with the data in …

Longbase Laser Strainmeter Measurements From The South Ramp Of The Yucca Mountain Facility, Frank K. Wyatt, Duncan C. Agnew, James N. Brune, Amy J. Smiecinski

Publications (YM)

Under subcontract (DOE/UCCSN DE-FC28-98NV12081, Task 7) from the Seismological Laboratory of the University of Nevada-Reno, the University of California, San Diego (UCSD), has designed, installed, and operated a laser strainmeter (LSM) in the Exploratory Studies Facility (ESF) at Yucca Mountain, Nevada. This instrument provides precise deformation monitoring of the (proposed) repository block. This document describes the history of the installation, outlines the principles of operation of the system, documents the integral recording and control system and file formats used, and provides information on how QA has been implemented, with the aim of being a self-contained description which could be used …

Task 1: Geodetic Monitoring Of The Yucca Mountain Region Using Continuous Global Positioning System Measurements, Jonathan Price

Publications (YM)

The principal purpose of the cooperative agreement is to develop and continue providing the public and the Yucca Mountain Site Characterization Office (YMSCO) with an independently derived, unbiased body of scientific and engineering data concerning the study of Yucca Mountain as a potential high level waste repository. Under this agreement, the University and Community College System of Nevada (UCCSN) will perform scientific or engineering research, and develop and foster collaborative working relationships between the Government and academic researchers. The following describes the objectives of Task 1 “Geodetic Monitoring of the Yucca Mountain Region Using Continuous Global Positioning System Measurements” under …

Seismicity In The Vicinity Of Yucca Mountain, Nevada, For The Period October 1, 1997 To September 20, 1999, David H. Von Seggern, Ken Smith, Glenn Biasi

Publications (YM)

Starting on October 1, 1995 the monitoring of seismicity within the southern Great Basin near Yucca Mountain was performed with a new digital network. This network features three-component recording with 24-bit A/D conversion in the field. Continuous data is collected at 20 sps, and event triggered windows are collected at 100 samples per second. A seismic bulletin of events is made by associating triggers occurring within a prescribed time window. classifying the local earthquake events, and locating the earthquakes and computing their magnitudes with conventional methods. This report covers the operational and seismic results of the third and fourth full …