[Aqualist] SHAPE update: October 2014

[Steven J Phipps]

Back in September 2013, SHAPE participants proposed a long list of 
projects. Below is a summary of the progress that has been made on several 
of these projects over the last year.

One of the aims of SHAPE was to extend the original INTIMATE timeframe 
(8-30 ka) back to 60 ka. Continuing the same approach that was taken 
during the Aus-INTIMATE compilation, the first stage of this has been to 
compile the published data for 30-60 ka for each of the regions: 
Australia, New Zealand, Antarctica and the Southern Ocean. Posters were 
presented on each of these regions at the 2014 AQUA Biennial Meeting in 
Mildura, Australia. It is clear that some regions have a lot more data 
than others and that more work is needed to refine these compilations.

For the Australian region, this is an interesting period as it is the time 
of human arrival and extinction of the megafauna. Recently there has been 
a lot of work on this time period. However many of the records are 
discontinuous. If you are interested or have any records to contribute to 
this time period there will hopefully be a meeting in Sydney or Wollongong 
in December 2014, contact Jessica Reeves.

In the New Zealand region there are continuous records from both lakes and 
speleothems. There are some detailed pollen records from lake sediments 
for this period and a master chronology has been developed from compiling 
speleothem data from Westland, South Island. Discontinuous records are 
also available from lakes, aeolian data and cosmogenic dates from glacial 
moraines. It appears to be a period of relatively cool and dry conditions. 
This project is being led by Drew Lorrey.

In New Zealand there are a number of widespread tephras across the north 
island between 30-60 ka. One of these tephras, the Rotoehu, was recently 
dated using U/Th and He dating and its age has been refined to 45 ka. 
Other tephras from this time period will be dated using a similar method 
in the next year to refine the tephrochronology for this region, with the 
project being led by Kat Holt and David Lowe.

In Antarctica, ice cores and coastal records suggest that the ice sheet 
was not as extensive as the LGM and was more similar to the present 
extent. The aim is to use climate models to look at the potential reasons 
or mechanisms for a smaller ice sheet, despite the more glacial 
conditions. The project is being led by Duanne White.

In the oceans, records from the Southern Ocean appear to show millennial 
events similar to the Antarctic ice core records, whilst north of the 
Subtropical Front there is limited evidence for these events. However, 
there are some major issues with the chronology of the 30-60 ka period as 
there are few radiocarbon dates for many of these datasets and different 
datasets have been tuned to different ice core chronologies. This project 
is being led by Helen Bostock.

The Aus-INTIMATE compilation papers also identified some major gaps in our 
knowledge during the period 30-8 ka, and there are a couple of projects 
currently working on some of these gaps. One of these gaps was the LGM in 
Australia, for which there were relatively few records. This is currently 
being worked on with an ARC-funded project led by Jamie Shulmeister, and 
there was a session at AQUA 2014 in Mildura that focussed on the LGM in 
Australia. The data are challenging the dogma that Australia was dry and 
cold during the LGM, with some data suggesting that some regions were 
actually quite wet.

In New Zealand the Kawakawa tephra is being used as a chronological marker 
to compile all the climatic data for a short timeslice during the glacial 
(recently dated to 25.5 ka as part of Aus-INTIMATE). This is currently 
being compiled by Peter Almond and a paper will be submitted next year.

Another timeslice that is getting some attention is the Antarctic Cold 
Reversal (ACR; 15-13 ka). A total of 76 Southern Hemisphere palaeoclimate 
records have been compiled spanning the ACR interval at sub-500 year 
resolution, in addition to 8 palaeo-glacial records. The proxy data has 
been interpreted with the help of SynTraCE-21, a coupled climate model 
simulation conducted using the Community Climate System Model version 3 
(CCSM3). The comparison of proxy and models is one of the main aims of 
SHAPE. A draft of the paper for this project has been written by Joel 
Pedro and will be submitted in the near future.

As well as expanding our temporal coverage to 60 ka, we have also been 
working on better understanding the Holocene. Another project that has 
been comparing proxy data from New Zealand with global climate model PMIP 
outputs has been a project looking at the 6 ka timeslice. The PMIP outputs 
are also being compared to reconstructions from PICT 
(http://pict.niwa.co.nz/). There have been some very interesting results 
with regard to use of discrete taxa, which point to some seasonal 
sensitivity for some key marker species like the pollen Ascarina. Another 
interesting result is that Holocene glacial advances in Southern Alps were 
forced entirely by local insolation. A draft of the paper is currently 
being written by Drew Lorrey.

A one-year project looking at the early Holocene timeslice (12-6 ka) along 
a transect in the oceans has also recently been funded by the New Zealand 
Antarctic Research Institute (NZARI) and was initiated in October 2014. 
The project will be analysing a number of different temperature and 
productivity proxies from 7 cores that form a transect from the 
subtropical ocean to the Southern Ocean and compare with modelling outputs 
for this time period.

Other modelling projects are also looking at the Holocene and beyond. 
Transient simulations have been conducted by PMIP3 for the Last Millennium 
(850-1850 CE) and the Holocene (8-0 ka). Steven Phipps is also conducting 
a suite of new simulations spanning key periods of interest to SHAPE. 
These include 90-10 ka, 32-28 ka and 21-10 ka using the CSIRO Mk3L climate 
system model. These simulations will be made available to the SHAPE 
community.

Several other projects looking at ENSO (Drew Lorrey) and the monsoon 
(Claire Krause) are still in the preliminary phases, compiling datasets 
and the current literature. Also a project looking at changes in the 
westerlies from the glacial to the Holocene across the transition (Michael 
Shaun-Fletcher) and carbon isotopes and reservoir ages in the oceans 
(Helen Bostock). Some of these are more likely to progress in the next 
round of SHAPE.

As well as AQUA 2014, some of this preliminary work and the SHAPE project 
was presented by Helen Bostock at the INTIMATE meeting in Zaragoza, Spain, 
in June 2014. There was a very positive response from our European 
colleagues. There are several upcoming meetings which have SHAPE sessions 
where some of these projects will be discussed further. These include the 
upcoming Geosciences New Zealand conference in New Plymouth at the end of 
November, in which several of these projects and a couple of student 
projects that align with SHAPE are being presented. We also hope that many 
of these SHAPE projects will be presented at the INQUA conference in 
Nagoya in late July-early August 2015, where there is a SHAPE session and 
several other related sessions on the LGM, tephra and proxy development. 
The deadline for abstracts is the 20th December. This is also the deadline 
for AQUA travel grants for students and early career researchers.

In early 2015, we intend to hold a workshop in Sydney on climate modelling 
and palaeoclimate syntheses. We have received funding from INQUA which 
will allow us to subsidise attendance for ECRs. Look out for further 
information on this workshop shortly.

If you have anything to contribute to any of the above projects, we 
encourage you to get in touch with the leaders. If you have any ideas for 
how SHAPE should move forward beyond INQUA, then please get in touch with 
either Drew Lorrey (Andrew.Lorrey at niwa.co.nz) or Steven Phipps 
(s.phipps at unsw.edu.au ).

Compiled by Helen Bostock