New paper from my colleague and friend Julio Cauhy, reconstructing extreme rainfall events in Southern Brazil over the past 7.5 ka. Julio and colleagues combined cave monitoring with painstaking petrography and careful U-Th dating to analyse detrital flood layers in speleothems from Malfazido cave. They found that extreme rainfall events are influenced by Antarctic-tropical teleconnections, and that El Nino events had an important contribution in the last millennium. It's a fantastic piece of work!

https://www.nature.com/articles/s43247-026-03506-y

#QuaternaryScience #palaeoscience #palaeoclimatology #speleothem #CaveScience #Brazil #ExtremeRainfallEvents

New paper out today by my #MPIC colleague (and officemate/friend) Sam Nicholson, who looked at the climatic constraints on speleothem deposition in SW Asia - to the surprise of no-one who spends any time thinking about speleothem deposition, it's not straightforward!

https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G54103.1/723985/The-climatic-constraints-on-speleothem-deposition

#speleothem #Karst #paleoclimate #geology

I did something.
It's about the ColdBlob or SubPolarGyre or AMOC.
Specifically, about finding proxy locations on land for its annual evolution.

Taking SPG average sst in the months DJF and MAM, and computing also their year-on-year growth rate.

Then I computed the growth rate for DJF and MAM in all coordinates on land using Era5-Land 1951-2025.
And when the growthrate matches that of SPG within ±0.5 °C, it gets a ✅ .
6 ✅ per decade gets a 🔵 and counts toward selection.
Some more exclusion criteria applied, and I get a list of 315 locations on land for 🔵matching DJF growthrate, and a whopping additional 11,460 locations for MAM
In a 0.1x0.1 grid.

All DJF locations are in Papua. No proxies I know of have been recovered from Papua yet. I know all speleothems / stalagmites in caves🔴 , and all treerings ever analyzed🟢 , thanks to #NOAA .

But MAM °C has more locations. All of Indonesia basically is THE SPG in terms of growthrate. A few trees and speleothems match, one cave covers the whole #Holocene 🖖🏽
Large patches in Africa also match SPG in MAM. But only 2 short treering studies exist. No caves.
Middle and South America has plenty matching SPG MAM too, and a handful of trees and caves.

Yay.

#AMOC #climateChange #citizenscience #proxy #climateproxies #ColdBlob #SubPolarGyre
#Speleothem #treerings

Interesting paper out recently in ClimPast - subaquous speleothems record groundwater recharge in Mairs Cave, South Australia.

https://cp.copernicus.org/articles/21/857/2025/

#AusQuaternary #speleothem

Always a good day when friends have a good day! Out today in NATURE (!) from Monika Markowska - 8 million year record of recurrent humid phases in Arabia.

https://www.nature.com/articles/s41586-025-08859-6

#Quaternary #QuaternaryScience #speleothem #speleothems #palaeoclimate

Just published in Organic Geochemistry, "Fire-induced shifts in stalagmite organic matter mapped using Synchrotron infrared microspectroscopy", led by #ANSTO colleague Dr. Liza McDonough. We demonstrate for the first time that Synchrotron IRM is a promising non-destructive, high resolution (5 µm) technique for analysing stalagmite organic matter. The paper can be found #OpenAccess here: https://doi.org/10.1016/j.orggeochem.2024.104842

#speleothem #stalagmite #organicMatter #pastClimate #geochemistry #UNSW

@Andbaker