When you start on your journey to Ithaca,
then pray that the road is long,
full of adventure, full of knowledge.
Do not fear the Lestrygonians
and the Cyclopes and the angry Poseidon.
You will never meet such as these on your path,
if your thoughts remain lofty, if a fine
emotion touches your body and your spirit.
You will never meet the Lestrygonians,
the Cyclopes and the fierce Poseidon,
if you do not carry them within your soul,
if your soul does not raise them up before you.
Then pray that the road is long.
That the summer mornings are many,
that you will enter ports seen for the first time
with such pleasure, with such joy!
Stop at Phoenician markets,
and purchase fine merchandise,
mother-of-pearl and corals, amber and ebony,
and pleasurable perfumes of all kinds,
buy as many pleasurable perfumes as you can;
visit hosts of Egyptian cities,
to learn and learn from those who have knowledge.
Always keep Ithaca fixed in your mind.
To arrive there is your ultimate goal.
But do not hurry the voyage at all.
It is better to let it last for long years;
and even to anchor at the isle when you are old,
rich with all that you have gained on the way,
not expecting that Ithaca will offer you riches.
Ithaca has given you the beautiful voyage.
Without her you would never have taken the road.
But she has nothing more to give you.
And if you find her poor, Ithaca has not defrauded you.
With the great wisdom you have gained, with so much experience,
you must surely have understood by then what Ithacas mean.
By K. P. Kavafis (C. P. Cavafy), translation by Rae Dalven
כִּי תֵּצֵא בַּדֶּרֶךְ אֶל אִיתָקָה
שְׁאַל כִּי תֶּאֱרַךְ דַּרְכְּךָ מְאֹד
מְלֵאָה בְּהַרְפַּתְקָאוֹת, מְלֵאָה בְּדַעַת.
אַל תִּירָא אֶת הַלַּסְטְרִיגוֹנִים וְאֶת הַקִּיקְלוֹפִּים
אַל תִּירָא אֶת פּוֹסֵידוֹן הַמִּשְׁתּוֹלֵל.
לְעוֹלָם לֹא תִּמְצְאֵם עַל דַּרְכְּךָ
כָּל עוֹד מַחְשְׁבוֹתֶיךָ נִשָּׂאוֹת, וְרֶגֶשׁ מְעֻלֶּה
מַפְעִים אֶת נַפְשְׁךָ וְאֶת גּוּפְךָ מַנְהִיג.
לֹא תִּתָּקֵל בַּלַּסְטְרִיגוֹנִים וּבַקִּיקְלוֹפִּים
וְלֹא בְּפּוֹסֵידוֹן הַזּוֹעֵם, אֶלָּא אִם כֵּן
תַּעֲמִידֵם לְפָנֶיךָ נַפְשְׁךָ.
שְׁאַל כִּי תֶּאֱרַךְ דַּרְכְּךָ מְאֹד.
כִּי בִּבְקָרִים רַבִּים שֶׁל קַיִץ תִּכָּנֵס
בְּחֶדְוָה, בִּפְלִיאָה רַבָּה כָּל כָּךְ
אֶל נְמֵלִים שֶׁלֹּא רָאִיתָ מֵעוֹלָם.
בְּתַחֲנוֹת-מִסְחָר פֵינִיקִיּוֹת תַּעֲגֹן
תִּקְנֶה סְחוֹרוֹת מְשֻׁבָּחוֹת לָרֹב,
פְּנִינִים וְאַלְמֻגִּים, עִנְבָּר וְהָבְנֶה,
וּמִינִים שׁוֹנִים שֶׁל בְּשָׂמִים טוֹבִים
כְּכָל שֶׁרַק תִּמְצָא בְּשָׂמִים טוֹבִים.
עָלֶיךָ לְבַקֵּר בְּהַרְבֵּה עָרֵי מִצְרַיִם
לִלְמֹד, לִלְמֹד מֵאֵלֶּה הַיּוֹדְעִים.
וְכָל הַזְּמַן חֲשֹׁב עַל אִיתָקָה
כִּי יִעוּדְךָ הוּא לְהַגִּיעַ שָׁמָּה.
אַךְ אַל לְךָ לְהָחִישׁ אֶת מַסָּעֲךָ
מוּטָב שֶׁיִּמָּשֵׁךְ שָׁנִים רַבּוֹת.
שֶׁתַּגִּיעַ אֶל הָאִי שֶׁלְּךָ זָקֵן
עָשִׁיר בְּכָל מַה שֶּׁרָכַשְׁתָּ בַּדֶּרֶךְ.
אַל תְּצַפֶּה שֶׁאִיתָקָה תַּעֲנִיק לְךָ עשֶׁר.
אִיתָקָה הֶעֱנִיקָה לְךָ מַסָּע יָפֶה
אִלְמָלֵא הִיא לֹא הָיִיתָ כְּלָל יוֹצֵא לַדֶּרֶךְ.
יוֹתֵר מִזֶּה הִיא לֹא תּוּכַל לָתֵת.
וְהָיָה כִּי תִּמְצָאֶנָּה עֲנִיָּה - לֹא רִמְּתָה אוֹתְךָ אִיתָקָה.
וְכַאֲשֶׁר תָּשׁוּב, וְאַתָּה חָכָם, רַב-נִסָּיוֹן,
תּוּכַל אָז לְהָבִין מַה הֵן אִיתָקוֹת אֵלֶּה.
קונסטנדינוס קוואפיס, תרגום מיוונית: יורם ברונובסקי
מתוך קונסטנדינוס קוואפיס, כל השירים. הוצאת כרמל
The occurrence of earthquakes has been monitored with seismographs since the late 19th century. Palaeoseismology is the branch of geology that aims at recovering the earthquake history prior to the deployment of modern seismographs. On-fault research recovers the earthquakes that ruptured the surface along particular fault planes, while off-fault research relies on the effects of earthquake shaking on geological units (e.g., formation of seismites, landslides, rockfalls, liquefaction etc.). My on-fault research focuses on the activity of the Dead Sea Fault. Off-fault research is described below.
Seismites and palaeoclimate in the Dead Sea core
The Dead Sea Deep Drilling Project, which was carried out starting in 2010-2011 recovered a continuous 220-ka-long sedimentary sequence from the Dead Sea depocenter. The core provides annual/seasonal time resolution record of the environmental, climatic, seismic, and geomagnetic history of the region. A ~460-m main core, with over 85% of recovery, was obtained at ~300 m water depth at the deepest area of the lake. A second drill site was near the shore. The sedimentary record includes several sequences of salt layers interbedded with laminated mud. Several groups in Israel as well as in Germany, US, Switzerland, and Japan, study the cores. My group examines the drill cores in order to understand how the deep basin sediments reacted to earthquake vibrations, compare the seismite record with that from the margins, and document and analyze the longest continuous earthquake record on Earth.
The core record also provides high-resolution information on the sediment supply to the lake depocenter, which we interpret in terms of climate characteristics.
Clastic dikes are cross-cutting (discordant), tabular bodies that are filled with sediment. The dikes provide indications for the regional stress regime and the sediment conditions at the time of emplacement.
In the Dead Sea basin Early Holocene seismic activity triggered fluidization and clastic-dike emplacement within Late Pleistocene lacustrine Lisan Formation sediments. Hundreds of opening-mode dikes were documented in four distinct sites in relatively small areas (up to 5 sq.km): Bet Ha’Arava, Masada Plain, Nahal Amazyahu, and Ami’az Plain, where a radial system converges at an active salt intrusion (diapir).
© Shmulik Marco
Archaeological structures that were damaged by earthquakes are abundant throughout the Levant. They provide us with precious information on the pre-seismograph history of earthquakes, their locations, sizes, and source characteristics. After being weakened by damage, these structures become even more vulnerable to futue earthquakes that will surely hit the region again, endangering unique irreplaceable monuments and sites of our cultural heritage. Hence, archaeoseismology is a multidisciplinary research field that combines archaeology, history, geology, structural engineering, and seismology.
Our goal is to reconstruct the earthquake history of the region and to determine the vulnerability of major sites, suggest protection measures, and propose priorities for retrofitting key structures.
Superb outcrops of a salt diapir and surrounding rocks at Mount Sedom (aka Sodom), located at the southwestern side of the Dead Sea Basin, present an exceptional opportunity for detailed analysis of rock salt movement and the associated sedimentary and structural record of its movement.
In order to record the secular variation of the geomagnetic field in the past we measure the magnetization of lake sediments and archaeological artifacts that were heated to above the Currie temperature.
The records of the Earth's magnetic field reversals is used to refine age determinations of key geological units. We apply this method for resolving the structural evolution of the Dead Sea Fault and adjacent terranes.
I was introduced to the paleomagnetic research by Hagai Ron, the pioneer of the paleomagnetic research in Israel, who was one of my MSc and PhD supervisors.
Hagai, a friend, a mentor and teacher, and a leader passed away in September 10, 2012.
© Shmulik Marco
We use airborne laser scanning to characterize surface processes in response to the receding Dead Sea level, in particular the formation of shorelines, sinkholes, and channel incision in recently-exposed terrain.
© Shmulik Marco
We measure the anisotropy of the magnetic susceptibility (AMS) in order to resolve flow directions of clastic rocks and to determine the strain fields near faults.
The relationship between a small applied magnetic field vector H and the induced magnetization vector M is the magnetic susceptibility. If the magnetic response of a material depends on the orientation of the applied field - it is anisotropic.
We are indebted to Tahar AÏfa, who was our mentor and taught us the tricks of the trade in the early days of the research.
Seismites and soft sediment deformation (SSD)
Seismites are sedimentary units that exhibit earthquake-triggered deformation. We have been documenting the temporal and spatial distribution of seismites along the Dead Sea Fault since the early 1990s. Subsequently we started to investigate the structure and the physical principles that control the seismite formation in order to characterize the triggering earthquakes. Spectacular exposures of various types of seismites, in particular slump sheets that include recumbent folds, fold and thrust structures, and upward-finining breccias, which indicate subaqueous formation. We notice striking geometrical similarities between the structures, which were formed during high velocity slumping of low viscosity sediments, and large fold and thrust structures in mountain belts, which involve high viscosity rocks and low velocity deformation.