Radiogenic isotopic mapping of late Cenozoic eolian and hemipelagic sediment distribution in the east-central Pacific

2006 ◽  
Vol 248 (3-4) ◽  
pp. 840-850 ◽  
Author(s):  
A STANCIN ◽  
J GLEASON ◽  
D REA ◽  
R OWEN ◽  
T MOOREJR ◽  
...  
Keyword(s):  
Late Cenozoic ◽  
Central Pacific ◽  
Sediment Distribution ◽  
East Central ◽  
Hemipelagic Sediment

scholarly journals Ship- and island-based soundings from the 2016 El Niño Rapid Response (ENRR) field campaign

2018 ◽  
Author(s):  
Leslie M. Hartten ◽  
Christopher J. Cox ◽  
Paul E. Johnston ◽  
Daniel E. Wolfe ◽  
Scott Abbott ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Rapid Response ◽  
Public Access ◽  
Central Pacific ◽  
Quasi Biennial Oscillation ◽  
East Central ◽  
Field Campaign ◽  
Central Pacific Ocean ◽  
Christmas Island

Abstract. As the 2015/2016 El Niño was gathering strength in late 2015, scientists at the Earth System Research Laboratory's Physical Sciences Division proposed and led the implementation of NOAA's El Niño Rapid Response (ENRR) Field Campaign. ENRR observations included wind and thermodynamic profiles of the atmosphere over the near-equatorial east-central Pacific Ocean, many of which were collected from two field sites and transmitted in near-real time for inclusion in global forecasting models. From 26 January to 28 March 2016, twice-daily rawinsonde observations were made from Kiritimati (pronounced Christmas) Island (2.0°N, 157.4°E; call sign CXENRR). From 16 February to 16 March 2016, three to eight radiosondes were launched each day from the NOAA Ship Ronald H. Brown (allocated call sign WTEC) as it travelled southeast from Hawaii to service Tropical Atmosphere Ocean (TAO) buoys along longitudes 140°W and 125°W and then north to San Diego, California. Both the rapid and the remote nature of these deployments created particular difficulties in collecting and disseminating the soundings; these are described together with the methods used to reprocess the data after the field campaign finished. The reprocessed and lightly quality-controlled data have been put into an easy-to-read text format, qualifying them to be termed Level 2 soundings. They are archived and freely available for public access at NOAA's National Centers for Environmental Information (NCEI) in the form of two separate data sets: one consisting of 125 soundings from Kiritimati Island (doi:10.7289/V55Q4T5K), the other of 193 soundings from the NOAA Ship Ronald H. Brown (doi:10.7289/V5X63K15). Of the Kiritimati soundings, 94 % reached the tropopause and 88 % reached 40 hPa, while 89 % of the ship's soundings reached the tropopause and 87 % reached 40 hPa. The soundings captured the repeated advance and retreat of the ITCZ at Kiritimati, a variety of marine tropospheric environments encountered by the ship, and lower-stratospheric features of the 2015–2016 QBO (quasi-biennial oscillation), all providing a rich view of the local atmosphere's response to the east-central Pacific's extremely warm waters during the 2015/16 El Niño.

COMPRESSIONAL GROWTH OF THE MINERVA ANTICLINE, OTWAY BASIN, SOUTHEAST AUSTRALIA—EVIDENCE OF OBLIQUE RIFTING

2004 ◽  
Vol 44 (1) ◽  
pp. 463 ◽  
Author(s):  
C.L. Schneider ◽  
K.C. Hill ◽  
N. Hoffman
Keyword(s):  
Early Cretaceous ◽  
Normal Faults ◽  
Sediment Distribution ◽  
East Central ◽  
Sea Floor ◽  
Structural Style ◽  
Isopach Maps ◽  
Structural Growth ◽  
Oblique Rifting ◽  
Sea Floor Spreading

Shipwreck Trough, east-central Otway Basin, evolved through Early Cretaceous to Santonian extension, followed by Campanian–Paleocene and Miocene to Recent pulses of compression.Onshore to offshore correlation of seismic sequences combined with 3D seismic mapping reveals that the Minerva anticline is located above an Early Cretaceous, northeast trending, basement-involved, graben. The graben-forming, northeast and north–south trending faults became largely inactive prior to the end of the Early Cretaceous. During the Turonian to Santonian, the northeast trending Point Ronald anticline and newly formed east–west trending normal faults controlled sediment distribution. The structural style changed in the Campanian as the northeast trending Minerva anticline began to form with a coeval, northwest-trending, axial-perpendicular fault array located along the crest of the fold. The location and orientation of this fault set is consistent with a compressional mechanism for fold growth. Similar compressional folding events during the Miocene–Recent modified and tightened the fold. Isopach maps show that during the Campanian to Maastrichtian, sediment thinned onto the nascent Minerva anticline, but accommodation rate outpaced structural growth, preserving a continuous sedimentary sequence.The timing of compressional fold growth is enigmatic. Campanian–Maastrichtian compression at the Minerva anticline was synchronous with over 10 km of extension accommodated by the Tartwaup–Mussel hingeline, 50 km to the south. Although the compression may be far-field effects associated with Tasman Basin sea floor spreading, we speculate that the Minerva anticline grew by transpression within a larger left-lateral transtensional Shipwreck Trough.

Evolution of Triple Junctions

1975 ◽  
Vol 12 (3) ◽  
pp. 516-519 ◽  
Author(s):  
Derek York
Keyword(s):  
Triple Junction ◽  
Angular Spread ◽  
Triple Junctions ◽  
Central Pacific ◽  
East Central ◽  
Spreading Ridges

The condition for stability at a triple junction of three normally spreading ridges should read: all ridge orientations may be stable if and only if the three ridge elements occupy an angular spread of more than 180°. This consideration leads to the conclusion that, in one mode of formation of an RRR triple junction, at least one active ridge segment should be extinguished. A fossil rise in the east-central Pacific is examined as a possible illustration of the argument.

Interannual variability of the seesaw mode of the interface between the Indian and East Asian summer monsoons

2020 ◽  
Author(s):  
Ruo Wen Yang ◽  
Jian Wang
Keyword(s):  
South China Sea ◽  
Summer Monsoon ◽  
East Asian ◽  
Tropical Indian Ocean ◽  
Summer Rainfall ◽  
Monsoon Trough ◽  
Normal Position ◽  
Central Pacific ◽  
East Central ◽  
Asian Summer

<p>The relation between the seesaw mode of the Interface between the Indian summer monsoon and East Asian summer monsoon (IIE) and the South China Sea summer monsoon trough (SCSSMT) and the Indian summer monsoon trough (ISMT) is investigated using two atmospheric reanalyses together with outgoing longwave radiation, sea surface temperature (SST), and gridded precipitation datasets. Canonical correlation analysis combined with empirical orthogonal functions, correlation, and composite analysis are employed. Results indicate that a stronger ISMT and SCSSMT resulting from colder SST over the tropical Indian Ocean and tropical east-central Pacific cause the IIE to deviate from its normal position in an anticlockwise direction, with a node at around 22°N. This leads to heavier than normal summer rainfall over the north-central Indian subcontinent and South China Sea, but weaker than normal from the low and middle reaches of the Yangtze River and South Korea to central Japan. A weaker ISMT and SCSSMT resulting from warmer SST over the tropical Indian Ocean and tropical east-central Pacific causes the IIE to deviate from its normal position in a clockwise direction, and the anomalous summer rainfall pattern is the opposite of that for the stronger troughs. Further analysis indicates that the SCSSMT plays a crucial role in the evolution of the IIE seesaw mode. The latitudinal difference between the IMST and SCSSMT may be one of the most important reasons for the formation of the IIE seesaw mode.</p>

scholarly journals Radial S wave velocity structure of the D" region under a spot of the east central Pacific Ocean

2012 ◽  
Vol 51 (3) ◽  
Author(s):  
Luis F. Terán-Mendieta. ◽  
Raúl. W. Valenzuela
Keyword(s):  
Pacific Ocean ◽  
Wave Velocity ◽  
Velocity Structure ◽  
S Wave ◽  
Central Pacific ◽  
East Central ◽  
Central Pacific Ocean ◽  
D Region

Se determino la estructura radial de velocidades para la onda S en la base del manto en un área del Océano Pacifico centro-oriental centrada en los 19°N, 132°0. Se aplico la técnica de la constante de disipación en el dominio de la frecuencia a las ondas S y Sdiff de un sismo producido en las islas Tonga y registrado en el noreste de los Estados Unidos. Se trabajo con 29 modelos diferentes, entre los cuales se incluían modelos con una discontinuidad de la velocidad y también el Modelo Preliminar de Referencia de la Tierra (PREM). De acuerdo con el ajuste a la constante de disipación en el dominio de la frecuencia y a las formas de onda en el dominio del tiempo, se considero que PREM es el mejor modelo. Esto implica que en esta ubicación D" tiene un espesor de 150 km y un gradiente de velocidad ligeramente negativo conforme aumenta la profundidad. No se encontró una discontinuidad de la velocidad en la parte superior de D". La estructura de velocidades observada es consistente con el comportamiento de D"como una capa térmica limítrofe y también con la posibilidad de que el material del manto se enriquezca en hierro como consecuencia de reacciones químicas con el núcleo. Ademas este modelo sugiere que en esta región existen temperaturas ligeramente elevadas en la base del manto. Por otra parte, no se esperaría encontrar una discontinuidad en esta zona puesto que ahí no se ha producido subducción en los últimos 180 millones de años.

Chemical analyses, correlations, and ages of late Cenozoic tephra units of east-central and Southern California

1980 ◽  
Author(s):  
Andrei M. Sarna-Wojcicki ◽  
H.W. Bowman ◽  
C.E. Meyer ◽  
P.C. Russell ◽  
Frank Asaro ◽  
...  
Keyword(s):  
Southern California ◽  
Chemical Analyses ◽  
Late Cenozoic ◽  
East Central
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