The Wister Mud Pot Lineament: Southeastward Extension or Abandoned Strand of the San Andreas Fault?

We present the results of a survey of mud pots in the Wister Unit of the Imperial Wildlife Area. Thirty-three mud pots, pot clusters, or related geothermal vents (hundreds of pots in all) were identified, and most were found to cluster along a northwest-trending line that is more or less coincident with the postulated Sand Hills fault. An extrapolation of the trace of the San Andreas fault southeastward from its accepted terminus north of Bombay Beach very nearly coincides with the mud pot lineament and may represent a surface manifestation of the San Andreas fault southeast of the Salton Sea. Additionally, a recent survey of vents near Mullet Island in the Salton Sea revealed eight areas along a northwest-striking line where gas was bubbling up through the water and in two cases hot mud and water were being violently ejected

The slip history of the 1994 Northridge, California, earthquake determined from strong-motion, teleseismic, GPS, and leveling data

We present a rupture model of the Northridge earthquake, determined from the joint inversion of near-source strong ground motion recordings, P and SH teleseismic body waves, Global Positioning System (GPS) displacement vectors, and permanent uplift measured along leveling lines. The fault is defined to strike 122° and dip 40° to the south-southwest. The average rake vector is determined to be 101°, and average slip is 1.3 m; the peak slip reaches about 3 m. Our estimate of the seismic moment is 1.3 ± 0.2 × 10^(26) dyne-cm (potency of 0.4 km3). The rupture area is small relative to the overall aftershock dimensions and is approximately 15 km along strike, nearly 20 km in the dip direction, and there is no indication of slip shallower than about 5 to 6 km. The up-dip, strong-motion velocity waveforms are dominated by large S-wave pulses attributed to source directivity and are comprised of at least 2 to 3 distinct arrivals (a few seconds apart). Stations at southern azimuths indicate two main S-wave arrivals separated longer in time (about 4 to 5 sec). These observations are best modeled with a complex distribution of subevents: The initial S-wave arrival comes from an asperity that begins at the hypocenter and extends up-dip and to the north where a second, larger subevent is centered (about 12 km away). The secondary S arrivals at southern azimuths are best fit with additional energy radiation from another high slip region at a depth of 19 km, 8 km west of the hypocenter. The resolving power of the individual data sets is examined by predicting the geodetic (GPS and leveling) displacements with the dislocation model determined from the waveform data, and vice versa, and also by analyzing how well the teleseismic solution predicts the recorded strong motions. The general features of the geodetic displacements are not well predicted from the model determined independently from the strong-motion data; likewise, the slip model determined from geodetic data does not adequately reproduce the strong-motion characteristics. Whereas a particularly smooth slip pattern is sufficient to satisfy the geodetic data, the strong-motion and teleseismic data require a more heterogeneous slip distribution in order to reproduce the velocity amplitudes and frequency content. Although the teleseismic model can adequately reproduce the overall amplitude and frequency content of the strong-motion velocity recordings, it does a poor job of predicting the geodetic data. Consequently, a robust representation of the slip history and heterogeneity requires a combined analysis of these data sets

The Ursinus Weekly, March 19, 1956

MS-WSGA pass new class rules; Discuss govt. merger • Holcombe, Walker lead S.E.-PFTA • Sella, McCoy view Dartmouth meeting • Dr. Parsons announces changes in calendar • May Day dances still offer a few positions • Y discusses cuts, race relations; Commissions to meet Wednesday • Foard to succeed Winchester as editor; Will assume duties today • APO plans contest for CC drive • Forum hears of African problem • Faculty minstrel planned for show • Business Club visits industry • Choir presents several concerts • Audrey Cale to speak to I.R.C. tonight • Editorial: Ave atque vale (hail and farewell); New insight • Feature staff laughs at itself • Letters to the editor • Feature editor reflects on his ideals, evaluates reality • Red Sox picked over Yankees and Indians in the official predictions • Swimmers finish 8th in competition • Badminton Belles end good season • Track prospects brighten as 28 candidates report • Girls b-ball team runs streak to 8 • Detailed account of government meeting where fourteen class rules were passed • Rev. F. I. Sheeder heads church publication group • The last time I seen Paris • Do you support red revolution in your backyard?https://digitalcommons.ursinus.edu/weekly/1446/thumbnail.jp

The Lantern Vol. 24, No. 2, March 1956

• Nee Collegium Emersonium • Two on the Aisle • Sheepherder Heard From • The Vicar of Wakefield • Miracle on Tisdam Avenue • Venus Observed • For Ginny\u27s Birthday, 1955 • It was a Sunset Stark and Barehttps://digitalcommons.ursinus.edu/lantern/1068/thumbnail.jp

The Ursinus Weekly, May 17, 1965

Michener to address Class of 1965 • UC awarded science grant • That was the Inter-Frat Spring weekend that was • Three Ursinus juniors to spend Summer in Europe • Agency plans diverse concerts for next season • Negro choir to present concert • Howard to attend Summer institute • Dr. Smith talks on timely topic • Staiger to lead science seminar • $10,000 presented to College to furnish new dining room • Editorial: A stomping time; Now\u27s your chance; Bomberger concert • Committee announces details of revised customs program • Last word • Souders plays his way through Ursinus College • Are the Zorbas right? • Lacrosse team undefeated • UC second in MACs: PMC wins by one point, 33-32 • Baseball team wins three: Nears tie for first place • Netmen lose to M\u27berg, LaSalle • Women netters win twice • Softballers rip E. S\u27burg • Greek gleaningshttps://digitalcommons.ursinus.edu/weekly/1250/thumbnail.jp

The Lantern Vol. 24, No. 3, May 1956

• Wedding Week in East Pookins • Playground • When the Moon • Love Song • Balladier • Soliloquy • The Search for Alfie Patch • How I Learned to Drive • The Hard-Backed Chair • Amicus • A Strange Experiencehttps://digitalcommons.ursinus.edu/lantern/1069/thumbnail.jp

The Ursinus Weekly, February 20, 1956

Mr. Cary speaks about his tour of Russia at Forum • Class rules comm. meets February 28 • Business Administration Club elects officers • Meistersingers and Chapel Choir get new choir gowns • Hamilton directs Campus Chest • YM-YWCA Cabinet discuss future plans at retreat • Pre-meds hear Dr. Wolffe; Plan trip • Bob Constable crowned king of the Lorelei, Fri. • Mr. Benjamin Fay speaks to APO • News on Bill Burger \u2754 • Selective Service test to be given Monday, March 5 • Editorial: Student day of prayer • Benefits of discussion in class • Changes appear in the Ursinus College catalogue • Lack of spirit, poor planning cause dead weekends at UC • Bucknell smashes Bruins; Knauf\u27s pin stops Hens • Gros\u27s clutch foul wins for Belles, 53-52 • Cagers mangle Garnet by 93-83 but drop Delaware, PMC decisions • Improving JVs, led by Watson, deserve credit • Ruby to appear May 20th; Most of work finished • Badminton squad wins first, 4-1 • Girls\u27 swimming team splits two • Fraternity row • Sorority row • Phila. Orchestra releases schedule for Feb. and Mar. • Ursinus welcomes new studentshttps://digitalcommons.ursinus.edu/weekly/1443/thumbnail.jp

Buried shallow fault slip from the South Napa earthquake revealed by near-field geodesy.

Earthquake-related fault slip in the upper hundreds of meters of Earths surface has remained largely unstudied because of challenges measuring deformation in the near field of a fault rupture. We analyze centimeter-scale accuracy mobile laser scanning (MLS) data of deformed vine rows within ±300 m of the principal surface expression of the M (magnitude) 6.0 2014 South Napa earthquake. Rather than assuming surface displacement equivalence to fault slip, we invert the near-field data with a model that allows for, but does not require, the fault to be buried below the surface. The inversion maps the position on a preexisting fault plane of a slip front that terminates ~3 to 25 m below the surface coseismically and within a few hours postseismically. The lack of surface-breaching fault slip is verified by two trenches. We estimate near-surface slip ranging from ~0.5 to 1.25 m. Surface displacement can underestimate fault slip by as much as 30%. This implies that similar biases could be present in short-term geologic slip rates used in seismic hazard analyses. Along strike and downdip, we find deficits in slip: The along-strike deficit is erased after ~1 month by afterslip. We find no evidence of off-fault deformation and conclude that the downdip shallow slip deficit for this event is likely an artifact. As near-field geodetic data rapidly proliferate and will become commonplace, we suggest that analyses of near-surface fault rupture should also use more sophisticated mechanical models and subsurface geomechanical tests

The Ursinus Weekly, February 12, 1962

Immortalized in fiction, poetry, Lorelei lends name to Ursinus • Two theologians visit U.C. campus this week; Seminary president, Convocation guest to speak • College President banquet speaker • Spring rushing periods begin • Auden to recite Tuesday at YMHA • Twelve frosh women to run for WSGA, WAA • PSEA to hear principal; U.C. to host conference • Troy Chapman returns; Discusses urban renewal • Editorial: For the love of Mike • Letters to the editor • Ursinus in the past • Cartoonist\u27s play: A review of Feiffer\u27s Crawling Arnold • Certain obscure ceremonials: The Locker-Lampson effect • Women hoopsters show no mercy • Ursinus grapplers grind two opponents; Elizabethtown, Lebanon Valley fall victim • Hoopsters bruise Blue Jays, 54 to 35 as nine game Bear losing skein ends • Bloodmobile here Monday afternoon • Dr. Armstrong seeking U.C. tourists for Europe • Graduate grants • Silver opinion contest conducted on campushttps://digitalcommons.ursinus.edu/weekly/1310/thumbnail.jp

The Ursinus Weekly, May 7, 1956

College Library vandalized; Files, matting are damaged • Y cabinet meets; New chairmen and leaders named • NSA conference report • MSGA officers to be elected in Wednesday voting • WAA banquet to be held on May 8 • Men\u27s government May 2nd election results announced • Curtain Club to hold elections on Tue., May 8 • Candidates for MSGA presidency state positions on government problems • YM-YWCA retreat held May 4, 5 & 6; Plans discussed • Demas chooses officers • Sigma Rho plans dinner-dance • Annual May Day program to include dances, concert, play • UC Curtain Club to present play on May 11 and 12 • Ursinus Band, Meistersingers to present concert • Deltas appoint new officials • Editorial: Neo-barbarism at Ursinus; Time for a change • Letters to the editor • Recall to reality • Reply to Dr. Baker\u27s navy article • Customs and campus opinions • Trackmen drop fourth to Garnets; Crushed in triangular meet Sat. • Belles drop first to W. Chester 3-2 • F & M hands netmen 4th loss • Netgals pickup 3rd, 4th straight win • IM softball teams move into action • Third unearned tally in 9th gives Bluehens 3-2 victory • Beta Sig picks officershttps://digitalcommons.ursinus.edu/weekly/1451/thumbnail.jp