☆Earth and Planetary Science Letters☆
2013/12/9-2013/12/15
1. Dynamics of the earth magnetic
field in the 10–75 kyr period comprising the Laschamp and Mono Lake excursions:
New results from the French Chaîne des Puys in a global perspective
Author(s):
Carlo Laj , Hervé Guillou , Catherine Kissel
Source:
Earth and Planetary Science Letters, Volume 387
DOI:
10.1016/j.epsl.2013.11.031
Keywords:
geomagnetic excursions; earth magnetic field intensity K/Ar dating; 40Ar/39Ar
dating; volcanic records
Highlights
• New
lava flows recording the intensity low of the Mono Lake.
• New
flows recording the Laschamp excursion with a mean age of 41.3±0.6
ka (2σ).
• ∼1500 yr
(intensity), 640 yr (directions) duration for Laschamp excursion.
• Full
intensity recover between the well distinct Laschamp and Mono Lake excursions.
• Rate
of decrease for the Laschamp excursion similar to that observed since 1840.
溶岩流の地磁気を用いて、75kaから10kaまでの、Mono
lake excursionとLaschamp excursionの記録を復元。方向と強度(directions and intensities)両方の復元を行い、その結果は堆積物や宇宙線生成核種(10Be and 36Cl)を用いた先行研究と一致していた。（強度の復元では、Laschampでは41.2±1.6 kaに、Mono
lake excursionでは34.2±1.2 kaに、強度の顕著な減少が見られた。）
また、”Mono lake”ではなくて、”Auckland
excursion”と呼ぶべきだと言う指摘をしている。Aucklandでは方向・強度・放射性年代が得られており、不明瞭な点無く復元された場所の名前を用いる、という伝統に則すると、”Auckland
excursion”の方が適切。
2. Ocean-atmosphere climate shift
during the mid-to-late Holocene transition
Author(s):
Audrey Morley , Yair Rosenthal , Peter deMenocal
Source:Earth
and Planetary Science Letters, Volume 388
DOI:
10.1016/j.epsl.2013.11.039
Keywords:
paleoceanography; ocean-atmosphere climate linkages; mid-Holocene climate
optimum; Eastern North Atlantic Central water circulation; NAO; orbital
insolation
Highlights
• The
mid-to-late Holocene transition: Dynamic response to gradual insolation
forcing.
• Central
Water circulation amplifies climate sensitivity to small insolation forcing.
• Focus
on modern NAO-AMO circulation modes, oversimplifies past climate dynamics.
• 1930s
regime shift: A possible analogue for climate dynamics during the HTM.
海底堆積物中の底生有孔虫のMg/Caを用いて0-5.5
kaの北大西洋中層水の水温を復元した結果、Eastern North Atlantic Central Waters
(ENACW)の水温が3.3kaから2.6kaにかけて∼1°±0.7 °C低下していたことが明らかになった。この記録は、ENACWの循環が緯度間の温度勾配の維持に重要な役割を果たしている(Holocene
Thermal Maximumから late-Holoceneへの転換期に緯度方向の熱輸送を減少させた)ことを示している。
☆Geochimica et Cosmochimica Acta☆
2013/12/9-2013/12/15
3. Biomineralization of
iron-phosphates in the water column of Lake Pavin (Massif Central, France)
Author(s):
Julie Cosmidis , Karim Benzerara , Guillaume Morin , Vincent Busigny , Oanez
Lebeau , Didier Jézéquel , Vincent Noël , Gabrielle Dublet , Guillaume Othmane
Source:Geochimica
et Cosmochimica Acta, Volume 126
DOI:
10.1016/j.gca.2013.10.037
☆Global and Planetary Change☆
2013/12/9-2013/12/15
4. Trends and acceleration in global
and regional sea levels since 1807
Author(s):
S. Jevrejeva , J.C. Moore , A. Grinsted , A. Matthews , G. Spada
DOI:
10.1016/j.gloplacha.2013.12.004
Keywords:
sea level trends; sea level acceleration; tide gauge records; GIA corrections
Highlights
• Updated
global and regional sea level rise since 1807
• Fastest
sea level rise in Arctic (3.8 mm · yr- 1) and Antarctica (3.5 mm · yr- 1)
• Acceleration
of 0.02 mm · yr- 2 in global sea level (1807–2010)
• Uncertainties
in gsl reconstruction due to GIA corrections are up to 0.3 mm · yr- 1
☆Palaeogeography, Palaeoclimatology, Palaeoecology☆
2013/12/9-2013/12/15
5. The Toarcian Oceanic Anoxic Event
in the Ionian Zone, Greece
Author(s):
N. Kafousia , V. Karakitsios , E. Mattioli , S. Kenjo , H.C. Jenkyns
Source:Palaeogeography,
Palaeoclimatology, Palaeoecology, Volume 393
DOI:
10.1016/j.palaeo.2013.11.013
Keywords:
Jurassic; Carbon isotopes; Chemostratigraphy; Calcareous nannofossils; T-OAE
Highlights
• A
high-resolution record of the T-OAE of the Ionian Zone has been established.
• Nannofossil
biostratigraphy allowed age assessment and correlation of sections.
• The
Pliensbachian/Toarcian boundary recognized in the Siniais Limestone formation.
• The
negative CIE occurs in NJT 6 Zone in all sections from Ionian Zone.
• A
positive CIE takes place in NJT 7 Zone in only one section (Petousi).
☆Quaternary Geochronology☆
2013/12/9-2013/12/15
6. Evaluation of the Rehydroxylation
Dating Method: Insights from a new measurement device
Author(s):
Maxime Le Goff , Yves Gallet
DOI:
10.1016/j.quageo.2013.12.001
Keywords:
rehydroxylation dating; ceramics; heating duration; archeology; archeomagnetism
Highlights
• New
multi-sample device for rehydroxylation dating is presented
• Heating
duration of samples at low and high temperatures is a critical parameter
• Long-term
sample mass stabilization not observed even after prolonged drying at 105°C
過去数百万年の古地磁気学のデータは、考古学的試料、火山岩、堆積物などの地磁気方向や強度の復元から得られている。従って、これらの試料の年代測定はとても重要である。考古学的試料（炉の壁面、陶器、レンガ、タイルなどの焼いた土）の欠片1つからでも年代測定ができるrehydroxylation (RHX) datingは、考古学的試料からの古地磁気データの年代の信頼性を向上する上で有力なツールである。この論文では、新しい機器を作ってrehydroxylation
(RHX) datingの手法を改良したが、この手法がさらに信頼できるものになるには、まだ試料の選定方法や手法の改良が必要である。
☆Quaternary Research☆
2013/12/9-2013/12/15
7. Millennial- to centennial-scale
climate periodicities and forcing mechanisms in the westernmost Mediterranean
for the past 20,000yr
Author(s):
Marta Rodrigo-Gámiz , Francisca Martínez-Ruiz , Francisco J. Rodríguez-Tovar ,
Francisco J. Jiménez-Espejo , Eulogio Pardo-Igúzquiza
DOI:
10.1016/j.yqres.2013.10.009
Keywords:
Geochemical proxies; Spectral cycles; Forcing mechanism; Last deglaciation;
Western Mediterranean
8. Sea-level and reef accretion
history of Marine Oxygen Isotope Stage 7 and late Stage 5 based on age and
facies of submerged late Pleistocene reefs, Oahu, Hawaii
Author(s):
Clark E. Sherman , Charles H. Fletcher , Ken H. Rubin , Kathleen R. Simmons ,
Walter H. Adey
DOI:
10.1016/j.yqres.2013.11.001
Keywords:
Hawaii; Pleistocene reef; Th–U dating; Reef facies; Pleistocene sea level
ハワイのオアフ島のサンゴ礁のハマサンゴ(P.lobata)のU-Th年代測定を行い、沈水しているテラスの大部分がMIS7のサンゴで形成されていることを明らかにした。このことから、MIS7の時期はこの地域の海水準が現在よりも9-20m低かったことが示唆された。
9. Assessing soil erosion and control
factors by radiometric technique in the source region of the Yellow River,
Tibetan Plateau
Author(s):
Yibo Wang , Fujun Niu , Qingbai Wu , Zeyong Gao
DOI:
10.1016/j.yqres.2013.11.003
Keywords:
Soil erosion; 137Cs method; Grassland degradation; Vegetation cover
Highlights
• Soil
erosion occurred in alpine meadow of the Yellow River, China.
• 137Cs
technique
• Soil
erosion intensity
☆Quaternary Science Reviews☆
2013/12/9-2013/12/15
10. Spectral absorbance of benthic
cladocerans as a new method for inferring past UV exposure of aquatic biota
Author(s):
Liisa Nevalainen , Milla Rautio
Source:Quaternary
Science Reviews, Volume 84
DOI:
10.1016/j.quascirev.2013.11.020
Keywords:
Alpine lakes; Boreal lakes; Cladocera; Fossil pigments; Lake sediments;
Melanin; Paleolimnology; UV radiation
Highlights
• Method
was developed to measure spectral absorbance of fossil cladoceran carapaces.
• Absorbance
spectrum was indicative of UV-protective melanin pigment in carapaces.
• Absorbance
values peaked during clear water periods in the lakes' history.
• Method
is usable for quaternary and ecological sciences with a focus on UV fluctuations.
水中生物相の受けた紫外線の記録を、湖沼堆積物中の底生のCladocera(枝角類：甲殻類に属する小型のプランクトン。ミジンコなど)の甲殻を用いて復元する手法を開発。2つの湖で過去300年間と過去1500年間の復元をそれぞれ行った結果、水がきれいな湖(オーストリアのアルプスにある湖)の方が、腐食性の北方の湖(東フィンランド)よりもUVを多く受けていたことがわかった。また、両者ともLIAの時にUVを多く受けていたことがわかり、寒冷な気候で一次生産が落ちたり、氷に覆われることで堆積物の流入が減っていた影響を反映している可能性が高いと考えられる。
11. Insights into continental
temperatures in the northwestern Black Sea area during the Last Glacial period
using branched tetraether lipids
Author(s):
Lise Sanchi , Guillemette Ménot , Edouard Bard
Source:Quaternary
Science Reviews, Volume 84
DOI:
10.1016/j.quascirev.2013.11.013
Keywords:
brGDGTs; Black Sea; Continental paleotemperatures; MBT/CBT; Last Glacial;
Abrupt climate changes
Highlights
• We
used branched GDGTs to infer Last Glacial temperatures in Black Sea catchment.
• We
propose temperature corrections regarding possible branched GDGT origins.
• Cold
spells related to the Younger Dryas, LGM and HE 2–3 are detected.
• Dansgaard–Oeschger
interstadials 2–8 are not imprinted in the signals.
☆Quaternary International
☆Marine Geology
2013/12/9-2013/12/15
特になし
☆Chemical Geology☆
2013/12/9-2013/12/15
新着なし
